Skip Navigation


International Immunology Advance Access originally published online on September 29, 2007
International Immunology 2007 19(11):1313-1318; doi:10.1093/intimm/dxm100
This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
19/11/1313    most recent
dxm100v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Heinze, M.
Right arrow Articles by Freund, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Heinze, M.
Right arrow Articles by Freund, C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?


© The Japanese Society for Immunology. 2007. All rights reserved. For permissions, please e-mail: journals.permissions@oxfordjournals.org

Investigating the functional role of CD2BP2 in T cells

Matthias Heinze, Michael Kofler and Christian Freund

Protein Engineering Group, Leibniz-Institute of Molecular Pharmacology and Free University Berlin, Robert-Rössle-Strasse 10, 13125 Berlin, Germany

Correspondence to: C. Freund; E-mail: freund{at}fmp-berlin.de


   Abstract
Top
 Abstract
Introduction
 Methods
 Results
 Discussion
 Funding
 References
 
The adaptor protein CD2-binding protein 2 (CD2BP2) confers binding to proline-rich sequences (PRS) via its GYF domain. In addition to the cytoplasmic domain of CD2, several other proteins were identified as interaction partners of CD2BP2, but the in vivo significance of these findings is unclear. We now show that CD2BP2’s nuclear localization is not changed when CD2 and CD2BP2 are co-expressed in HeLa cells, indicating that other PRS compete effectively for CD2BP2 binding in the nucleus. Since the CD2BP2-binding motifs of CD2 are known to be involved in cytokine signaling, we tested the effect of CD2BP2 knockdown in PBMCs on the expression of T-cell cytokines. No major difference in cytokine expression can be observed for primary cells transfected with CD2BP2-specific small interfering RNA. We conclude that CD2 signaling is at least partially independent of its in vitro binding partner CD2BP2.

Keywords: CD2, CD2BP2, cytokines, GYF, proline-rich sequences


   Introduction
Top
 Abstract
 Introduction
Methods
 Results
 Discussion
 Funding
 References
 
The stimulation of the TCR by MHC:peptide complexes is supported by many additional contacts within the interface of the T cell and the antigen-presenting cell (APC). The adhesion molecule CD2 accumulates in the contact zone upon antigen encounter and modulates TCR responsiveness (1, 2). Cytoplasmic signaling events are subsequently initiated that lead to cellular changes such as cytoskeletal rearrangements (3), change in adhesiveness (4) or phosphorylation of intracellular proteins (5). While the TCR conveys signals primarily by phosphorylated immune receptor tyrosine activation motifs, CD2 contains five proline-rich sequences (PRS) that mediate downstream signaling. Certain proteins containing src homology domain 3 (SH3 domain) interact with the PRS of CD2 and are important for the assembly of protein complexes at the CD2 cytoplasmic tail. The tyrosine kinase Fyn can bind to several of the PRS of CD2, thereby initiating the phosphorylation of downstream targets (6, 7). In addition, certain adaptor proteins that coordinate complex formation in T cells interact with CD2. For example, the CD2-associated protein binds to a C-terminal PRS of the CD2 cytoplasmic domain via its first SH3 domain and is critical for cytoskeletal changes in T cells (3). The adaptor protein CD2-binding protein 2 (CD2BP2) was the only protein found to confer binding to CD2 by means of a PRS recognition domain other than SH3 domain. The so-called GYF domain of CD2BP2 interacts with two membrane-proximal PPPPGHR motifs of CD2 that are important for CD2-dependent IL-2 production (8, 9). Structural studies showed that the SH3 domain of proto-oncogene tyrosine-protein kinase Fyn and the GYF domain of CD2BP2 can bind competitively to the CD2 cytoplasmic domain in vitro (7), and over-expression of the CD2BP2–GYF domain in Jurkat T cells led to a moderate overproduction of IL-2 (10). However, the recent findings that CD2BP2 predominantly localizes to the cell nucleus in different cell lines and its identification as a protein interacting with spliceosomal proteins called for further investigations under more physiological conditions (11–14). Co-expression of CD2 and CD2BP2 in HeLa cells shows distinct localization of the two proteins to the cell membrane and the nucleus, respectively. In primary cells, small interfering RNA (siRNA)-mediated reduction of CD2BP2 does not influence the production of IL-2 and other cytokines in response to CD2 stimulation. These findings suggest that CD2BP2 is not a key regulator of CD2-mediated IL-2 responses, but may have more subtle effects on cytokine expression as a nuclear protein associated with the splicing of mRNA.


   Methods
Top
 Abstract
 Introduction
 Methods
Results
 Discussion
 Funding
 References
 
Cell culture conditions and transfections
Human HeLa S3 cells were maintained in DMEM containing 10% (v/v) fetal bovine serum (FBS) (Biochrom) and penicillin/streptomycin (100 U ml–1). PBMCs were isolated from human blood by Ficoll density gradient centrifugation (Ficoll-Paque PLUS, Amersham) and 5 x 106 cells were transfected with 1.5 µg siRNA according to Amaxa’s optimized protocol for unstimulated human T cells. Immediately after transfection, PBMCs were cultured at 5 x 106 cells per ml in supplemented Rosewell Park Memorial Institute (RPMI) medium [10% (v/v) FBS, penicillin/streptomycin (100 U ml–1) and 2 mM L-glutamine].

siRNA duplexes
The CD2BP2 sequences targeted by the siRNAs are as follows: siRNA-1, 5'-ACGGTTGGCTATGCGTCTGAA-3' (Qiagen); siRNA-2, 5'-ACGCATTGACTTTGACCTCTA-3' (Qiagen); siRNA-3, 5'-GGCAAACACTCTTTGGATA-3' (Ambion) and negative control siRNA (with no homology to any known mammalian gene), 5'-AATTCTCCGAACGTGTCACGT-3' (Qiagen). SiRNA-1, siRNA-2 and control siRNA were labeled with Alexa-488 at their 3' ends. For the assessment of siRNA uptake by flow cytometry, PBMCs were transfected with 1.5 µg siRNA (Alexa-488-labeled siRNA-1 versus unlabeled negative control siRNA) according to the Amaxa’s optimized protocol for unstimulated human T cells. Immediately after transfection, cells were washed and analyzed by flow cytometry.

Measurement of IL-2 production by ELISA
SiRNA transfected PBMCs were cultured in 96-well plates for 48 h at 6 x 105 cells per well in 200 µl supplemented RPMI medium. For the last 24 h, 5 µl of CD2/CD2R antibody (Becton Dickinson, San Jose, USA) and 5 ng phorbol-12-myristate-13-acetate (PMA) were added. After 48 h of incubation, supernatants were collected and assayed for IL-2 using a human IL-2 ELISA kit (Endogen).

Cytokine flow cytometry
Cytokine flow cytometry (CFC) was performed according to the instructions of the BD FastImmune Intracellular Cytokine Detection Kit with slight modifications (Becton Dickinson). Briefly, PBMCs were stimulated for 5 h with BD CD2/CD2R antibodies (20 µl ml–1 medium) and PMA (25 ng ml–1). After 2 h, brefeldin A was added to a final concentration of 10 µg ml–1 to block the cellular release of cytokines. Following stimulation, PBMCs were first stained with peridinin chlorophyll protein–cyanine 5.5-conjugated anti-CD3 mAb (Sigma) and then permeablized and stained with allophycocyanin-conjugated anti-CD69 mAb, PE-conjugated anti-IL-2 mAb or PE-conjugated anti-IFN-{gamma} mAb or PE-conjugated anti-IL-10 mAb. The cells were then analyzed by sequential gating on cytokine/CD3 using a FACSCalibur flow cytometer operated by the CellQuest Software.

Detection of CD2BP2 in PBMC lysates by western blotting
Total protein lysates were prepared from 6 x 106 PBMCs for each sample. Therefore, cells were washed with PBS and lysed for 30 min by gentle rocking in lysis buffer [1% sodium cholate, 1 mM dithiothreitol, 2 mM EDTA and 1x concentration of ‘complete mini’ protease inhibitors (Roche) in PBS]. Lysates were normalized for total protein concentration using the BCA Protein Assay Kit (Pierce) and equal amounts of total lysate protein per sample were separated by SDS–PAGE. Proteins were then transferred onto nitrocellulose membranes. CD2BP2 protein levels were probed with anti-CD2BP2 antiserum (kindly provided by R. Lührmann, Göttingen, Germany, dilution 1:1000) and anti-GAPDH antibody (MAB374, Chemicon, dilution 1:100) as primary antibodies and IgG–Alexa 680 (Invitrogen, dilution 1:10 000) as well as IgG–IRDye 800 (Rockland, dilution 1:10 000) fluorophor-conjugated antibodies as secondary antibodies and finally analyzed by an Odyssey Infrared Imaging System equipped with Odyssey Application Software 2.1 (LI-COR Biosciences).

Statistical methods
Statistical analyses were performed using MicrocalTM Origin (Microcal software version 6.0). Intergroup comparisons were performed using the paired Student’s t-test. All P values were two tailed and considered significant if <0.05.

Co-localization studies
HeLa cells were grown on cover slips in 12-well plates and transiently transfected with CD2BP2-enhanced green fluorescent protein (EGFP) (13) and full-length CD2 using Lipofectamine plus (GIBCO) and 2 µg DNA per well. Forty-eight hours after transfection, cells were fixed with 4% para-formaldehyde/PBS for 10 min at room temperature and their nuclei were stained with Hoechst 33258 dye (5 µg ml–1 in H2O). For detection of CD2, cells were incubated with T111 primary (1:500 in PBS) and a Cy3-coupled anti-mouse secondary antibody (1:1000 in PBS) for 60 and 30 min, respectively. After washing with PBS, cells were mounted in Flouromount G (Southern Biotechnology) mounting medium for fluorescence microscopy. Images were recorded using a LSM 510 confocal laser scanning microscope (Carl Zeiss) with a x100/1.3 objective and an argon laser (488 nm) and were processed with the AXIOVISION software (Carl Zeiss).


   Results
Top
 Abstract
 Introduction
 Methods
 Results
Discussion
 Funding
 References
 
CD2 and CD2BP2 show distinct compartmentalization in HeLa cells
Yeast two-hybrid and nuclear magnetic resonance analyses were previously used to establish a physical interaction between the two proteins in vitro (7, 10, 15). A moderate influence of CD2BP2–GYF domain over-expression on IL-2 production was also reported and raised the question whether CD2BP2 is a more general regulator of cytokine production in T cells.

At first, we tested whether CD2 is able to recruit CD2BP2 under cellular conditions. Over-expression of EGFP–CD2BP2 and CD2 in HeLa cells showed distinct compartmentalization to the nucleus and the cell membrane, respectively (Fig. 1A). This pattern did not change when a CD2 tailless variant devoid of the CD2BP2–GYF-binding motifs was co-transfected with CD2BP2. Therefore, regardless of the presence or absence of its putative CD2BP2-binding motifs, over-expressed CD2 is not capable on its own to recruit CD2BP2. We conclude that additional molecular factors might be needed to achieve such a putative binding function in stimulated T cells.


Figure 1
View larger version (36K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 1. Effect of CD2 on CD2BP2 localization in HeLa cells. (A) CD2 full-length versus CD2 tailless deletion variant. HeLa S3 cells transiently expressing EGFP–CD2BP2 and either CD2 (A1) or a CD2 deletion variant, lacking the cytoplasmic tail (CD2taa236) (A2), were fixed 48 h after transfection. Nuclei were stained with Hoechst 33258 dye, CD2 and CD2taa236 were detected with T111 primary and a Cy3-coupled anti-mouse secondary antibody. Laser confocal images revealed CD2BP2 to localize predominantly to the nucleus, irrespective of the expressed CD2 variant. (B) CD2-stimulated cells versus unstimulated cells. HeLa S3 cells transiently expressing CD2BP2–YFP and CD2–CFP for 48 h were either stimulated via CD2 by T112 + 3 antibodies for 20 min (B1) or left unstimulated (B2). After fixation, cells were treated as described in (A).

 
To mimic activation of T cells, we stimulated over-expressed CD2 by a combination of CD2-binding and CD2 cross-linking antibodies. A similar pattern as for unstimulated cells was observed with distinct nuclear (CD2BP2) and membranous (CD2BP2) localization of the two proteins (Fig. 1B). CD2 cross-linking, as it is achieved by antibody capping, is not sufficient to change the predisposition of CD2BP2 for nuclear localization.

CD2BP2 knockdown in PBMCs
We utilized siRNA-mediated knockdown of endogenous CD2BP2 in PBMCs to test the role of the protein in cytokine signaling. Almost complete transfection of PBMCs with Alexa-488-labeled siRNA was achieved as judged by flow cytometry (Fig. 2A).


Figure 2
View larger version (23K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 2. SiRNA-mediated reduction of endogenous CD2BP2 in primary cells (PBMCs). (A) SiRNA transfer efficiency. PBMCs were electroporated either with Alexa-488-labeled or unlabeled siRNA. Immediately after electroporation, cells were analyzed by flow cytometry. Black curve: cells electroporated with unlabeled negative control siRNA; grey curve: cells electroporated with Alexa-488-labeled siRNA-1. (B) Anti-CD2BP2 immunoblot. PBMCs were electroporated with three different CD2BP2-specific siRNA duplexes or a negative control siRNA and cultured in RPMI medium. After 2 days, cells were lysed and lysates were normalized for total protein amounts. Solubilized proteins were separated by SDS–PAGE, immunoblotted with anti-CD2BP2 antiserum and GAPDH antibodies (loading control), subsequently incubated with fluorophor-conjugated secondary antibodies and finally analyszed by the Odyssey Infrared Imaging System. Using Odyssey Application Software, fluorescence intensities of labeled CD2BP2 and GAPDH were determined. Fluorescence intensities of the bands of the negative control sample were set to 100% and fluorescence intensities of the corresponding bands of the CD2BP2 siRNA-treated samples were normalized to this value. One representative example of several independently generated immunoblots is shown.

 
The extend of CD2BP2 knockdown in PBMCs after siRNA treatment was determined by performing anti-CD2BP2 western blots of PBMCs. These western blots revealed a significant CD2BP2 knockdown for the three different CD2BP2 siRNAs, varying between 40 and 60% (Fig. 2B). GAPDH was used as a negative and loading control and showed relatively constant amounts of protein on the same blotting membrane (Fig. 2B).

IL-2 production is normal in primary cells transfected with CD2BP2–siRNA
PBMCs expressing reduced levels of endogenous CD2BP2 after RNAi treatment were subsequently used for the measurement of cytokine levels produced by PBMCs. Therefore PBMCs were stimulated 24 h after siRNA transfection either by CD2-specific antibodies alone or in combination with PMA. After additional 24 h (48 h after siRNA transfection), IL-2 was measured by ELISA. Amounts of secreted IL-2 after stimulation with CD2 antibodies are shown in Fig. 3. Cells transfected with CD2BP2-specific siRNA showed no significant difference with regard to IL-2 production when compared with cells transfected with the negative control siRNA.


Figure 3
View larger version (18K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 3. IL-2 ELISA. PBMCs were electroporated either with three different CD2BP2-specific siRNAs (siRNA-1, siRNA-2 and siRNA-3) or negative control siRNA and cultured for 2 days. For the last 24 h, stimulating CD2 antibodies in combination with PMA (A) or stimulating CD2 antibodies alone (B) were added. Supernatants of each sample were tested for their IL-2 content by ELISA. For comparison, IL-2 contents in supernatants from unstimulated and PMA-only treated cells are shown.

 
Since ELISA-based IL-2 measurements rely on the accumulation of IL-2 in the medium over a long period of time, we used flow cytometric detection of intracellular cytokine as an alternative method to monitor IL-2 expression levels in T cells. Using this method, the analysis of defined cellular subsets within the mixture of PBMCs is possible. Cells transfected with the individual siRNAs were stimulated as described above and analyzed by CFC for co-expression of CD69 and IL-2 (Fig. 4). Similar to the results of the ELISA, there was no statistically relevant difference between CD2BP2-specific and negative control siRNA-treated cells. While we cannot definitively rule out an effect of CD2BP2 down-regulation on specific subsets of T cells, our data clearly indicate that CD2BP2 is not a general regulator of CD2-mediated IL-2 signaling in primary T cells.


Figure 4
View larger version (33K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 4. IL-2 CFC and assessment of CD69 expression. PBMCs were electroporated with CD2BP2-specific siRNAs (siRNA-1 and siRNA-3) or negative control siRNA. Two days after siRNA transfer, the cells were stimulated with CD2 antibodies in combination with PMA for 5 h and analyzed by CFC. The sub-population of CD3+ T cells was determined by gating and assessed for cells co-expressing CD69 and intracellular IL-2. (A) Typical example of CFC dot plots. Frequencies of CD69+IL-2+ cells (B) or CD69+ (C) cells were determined in six independent experiments and statistically analyzed for putative differences between the different siRNA treatment groups.

 
CD2BP2 knockdown does not affect additional CD2-related cytokines and the early activation marker CD69
We tested the influence of CD2BP2 down-regulation on the expression levels of marker molecules that are released after CD2 stimulation (16–18) and the early activation marker CD69 that is up-regulated after CD2 engagement (19). The intracellular staining of IFN-{gamma} and IL-10 did not show significant changes upon stimulation with CD2 antibodies in combination with PMA (Fig. 5). A minor, but statistically significant attenuation of CD69 expression (2.8%) was observed for the expression of CD69 when using the CD2BP2-specific siRNA-3 (Fig. 4C). However, since this effect is even smaller when using siRNA-1, we conclude that the majority of T cells is not affected by CD2BP2 down-regulation. Taken together, these measurements corroborate the hypothesis that CD2BP2 does not play a role as a general regulator of immune responses in primary human T cells.


Figure 5
View larger version (19K):
[in this window]
[in a new window]
[Download PowerPoint slide]
  		Fig. 5. IFN-{gamma} and IL-10 CFC. PBMCs were electroporated with CD2BP2-specific siRNA (siRNA-1) or negative control siRNA. Two or three days after siRNA transfer, cells were stimulated with CD2 antibodies in combination with PMA for 5 h and analyzed by CFC. Lymphocytes were gated by scatter and analyzed for the presence of CD3+IFN-{gamma}+ or CD3+IL-10+ cells. Frequencies of respective sub-populations were determined and statistically analyzed. Results are from two independent experiments.

 

   Discussion
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
Funding
 References
 
Co-transfection of CD2 and CD2BP2 into HeLa cells showed distinct localization to the membrane and the nucleus, respectively (Fig. 1). This pattern is observed with wild-type CD2 and a CD2 variant devoid of the cytoplasmic tail and its GYF domain consensus motifs. We conclude that CD2 on its own is unable to recruit CD2BP2, even at the relatively high concentrations achieved by over-expression in HeLa cells. Therefore, for the interaction to occur in T cells, additional factors have to be present that drive CD2BP2 out of the nucleus or lead to nuclear localization of the CD2 receptor. It will be challenging to pinpoint the conditions that may evoke co-localization of substantial amounts of the two proteins.

In regard to a CD2-signaling function of CD2BP2, our data suggest that there is no major contribution of the protein to CD2-mediated IL-2 production in PBMCs. This marks a difference to earlier experiments obtained by GYF domain over-expression in Jurkat T cells, where a moderate modulation of IL-2 production was observed for a GYF domain-only construct of CD2BP2 (10). However, since the knockdown achieved in this study is significant but not complete (between 40 and 60%), a more subtle role of CD2BP2 in signaling pathways leading to IL-2 production is still possible. Furthermore, cytokine production in primary cells, as they were used in this study, and in Jurkat T cells is distinct and may explain the observed differences. In addition to IL-2, there is no indication that CD2BP2 is substantially involved in additional CD2-mediated signaling events leading to the production of cytokines like IFN-{gamma} and IL-10. The slight attenuation of the expression of the early activation marker CD69 could indicate that more subtle effects for purified sub-populations of T cells could be observed in CD2BP2-deficient cells. Subsequent experiments using more physiological stimuli in combination with the analysis of certain T cell sub-populations should reveal such a specialized function of CD2BP2 in immune cell signaling.

Nuclear localization of CD2BP2 is in agreement with previous studies from our group that identified the core splicing protein Smith protein B/B' (SmB/B') as an interaction partner, co-localizing with CD2BP2 in the nucleus of HeLa cells (13). Furthermore, studies from another group showed that CD2BP2—also named U5-52K in this context—is part of the U5-small nuclear ribonucleoprotein particle (snRNP) prior to U4/U6.U5 tri-snRNP formation (12). A role in the biogenesis of the U5 snRNP has therefore been suggested. The proline-rich motifs bound by the CD2BP2–GYF domain under physiological conditions are still under debate. While SmB/B' is a constitutive component of all snRNPs, CD2BP2 was found neither in snRNPs other than U5 nor in the active splicing complex (12). Correspondingly, the interaction with SmB/B' might only appear temporarily. Since other spliceosomal proteins also contain binding sites for the CD2BP2–GYF domain, they might be more likely interaction partners at different stages of the U5 snRNP maturation pathway (20, 21). Bedford et al. (22) have hypothesized that a ‘proline-rich front’ is formed by spliceosomal proteins that attracts WW domain-containing proteins such as formin-binding protein 21 (22). Consistently, the transient character of GYF–PRS interactions could allow the binding to different spliceosomal proteins at different stages of snRNP assembly. Still, it has to be kept in mind that the interaction of GYF domains with their ligands are of low affinity and that CD2BP2:PRS complexes might be lost under the conditions used for purification of individual snRNP’s. In fact, a recent report shows the presence of CD2BP2 at later stages of the spliceosomal maturation pathway when using milder purification conditions (23).

In this context, it is interesting to note that the spliceosomal protein SmB/B' was found in the spreading initiation centers of primary fibroblasts (24). These structures are initial foci formed at the attachment sites that precede focal adhesions. The role of spliceosomal proteins for the formation of initial adhesion sites is still unclear, but mRNA seems not to be associated with these structures. It should therefore be tested whether CD2BP2 can be found at the membrane of T cells that actively migrate along epithelial surfaces or that are in close contact with an APC.

In summary, microscopic studies of over-expressed CD2 and CD2BP2 protein in HeLa cells and knockdown of CD2BP2 in primary PBMCs indicate that CD2BP2 is not a constitutive binding partner or key regulator of CD2-mediated signaling events. While CD2 is an adhesion molecule exerting its adhesive and signaling function primarily at the plasma membrane, CD2BP2 has a conserved role in nuclear processes associated with splicing. To find out, how and when these two processes may cross within the context of T cells during the course of their development and during activation will be a challenging task for future research.


   Funding
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Funding
References
 
Grant 0311879 from the Bundesministerium für Bildung und Forschung and grant FR-1325/3-1 from the Deutsche Forschungsgemeinschaft to C.F.


   Acknowledgements
 
We are thankful to Ellis Reinherz for providing the Flag-CD2BP2 transfected Jurkat J77 cell line, the CD2 expression constructs pMDC8-CD2, the anti-CD2 antibodies T 111, T 112 and T 113 and for fruitful discussions in regard to CD2BP2 function in T cells. Likewise we are thankful to R. Lührmann for providing CD2BP2/52K polyclonal antibodies. We appreciate the excellent technical assistance of Ulrike Schneweiss, Katharina Thiemke and Kathrin Motzny.


   Abbreviations
 
APC, antigen-presenting cell
CD2BP2, CD2-binding protein 2
CFC, cytokine flow cytometry
EGFP, enhanced green fluorescent protein
FBS, fetal bovine serum
GAPDH, glyceraldehyde-3-phosphate dehydrogenase
PMA, phorbol-12-myristate-13-acetate
PRS, proline-rich sequence
RPMI, Rosewell Park Memorial Institute
SH3 domain, src homology domain 3
siRNA, small interfering RNA
SmB/B', Smith protein B/B'
snRNP, small nuclear ribonucleoprotein particle

   Notes
 
Transmitting editor: S. Koyasu

Received 30 January 2007, accepted 4 September 2007.


   References
Top
 Abstract
 Introduction
 Methods
 Results
 Discussion
 Funding
 References
 

  1. Moingeon P, Chang HC, Wallner BP, Stebbins C, Frey AZ, Reinherz EL. Nature (1989) 339:312.[CrossRef][Medline]
  2. van Kooyk Y, Wiel-van Kemenade van de, Weder P, Kuijpers TW, Figdor CG. Nature (1989) 342:811.[CrossRef][Medline]
  3. Dustin ML, Olszowy MW, Holdorf AD, et al. Cell (1998) 94:667.[CrossRef][Web of Science][Medline]
  4. Li J, Nishizawa K, An W, et al. EMBO J. (1998) 17:7320.[CrossRef][Web of Science][Medline]
  5. Fukai I, Hussey RE, Sunder-Plassmann R, Reinherz EL. Eur. J. Immunol. (2000) 30:3507.[CrossRef][Web of Science][Medline]
  6. Lin H, Hutchcroft JE, Andoniou CE, Kamoun M, Band H, Bierer BE. J. Biol. Chem. (1998) 273:19914.[Abstract/Free Full Text]
  7. Freund C, Kuhne R, Yang H, Park S, Reinherz EL, Wagner G. EMBO J. (2002) 21:5985.[CrossRef][Web of Science][Medline]
  8. Chang HC, Moingeon P, Pedersen R, Lucich J, Stebbins C, Reinherz EL. J. Exp. Med. (1990) 172:351.[Abstract/Free Full Text]
  9. Hahn WC, Bierer BE. J. Exp. Med. (1993) 178:1831.[Abstract/Free Full Text]
  10. Nishizawa K, Freund C, Li J, Wagner G, Reinherz EL. Proc. Natl Acad. Sci. USA (1998) 95:14897.[Abstract/Free Full Text]
  11. Hartmuth K, Urlaub H, Vornlocher HP, et al. Proc. Natl Acad. Sci. USA (2002) 99:16719.[Abstract/Free Full Text]
  12. Laggerbauer B, Liu S, Makarov E, et al. RNA (2005) 11:598.[Abstract/Free Full Text]
  13. Kofler M, Heuer K, Zech T, Freund C. J. Biol. Chem. (2004) 279:28292.[Abstract/Free Full Text]
  14. Kofler M, Motzny K, Beyermann M, Freund C. J. Biol. Chem. (2005) 280:33397.[Abstract/Free Full Text]
  15. Freund C, Dotsch V, Nishizawa K, Reinherz EL, Wagner G. Nat. Struct. Biol. (1999) 6:656.[CrossRef][Web of Science][Medline]
  16. Schwarz M, Majdic O, Knapp W, Holter W. Immunology (1995) 86:364.[Web of Science][Medline]
  17. Bullens DM, Rafiq K, Charitidou L, et al. Int. Immunol. (2001) 13:181.[Abstract/Free Full Text]
  18. Wakkach A, Cottrez F, Groux H. J. Immunol. (2001) 167:3107.[Abstract/Free Full Text]
  19. Sasada T, Yang H, Reinherz EL. J. Immunol. (2002) 168:1113.[Abstract/Free Full Text]
  20. Kofler M, Motzny K, Freund C. Mol. Cell. Proteomics (2005) 4:1797.[Abstract/Free Full Text]
  21. Komuro A, Saeki M, Kato S. J. Biol. Chem. (1999) 274:36513.[Abstract/Free Full Text]
  22. Bedford MT, Chan DC, Leder P. EMBO J. (1997) 16:2376.[CrossRef][Web of Science][Medline]
  23. Deckert J, Hartmuth K, Boehringer D, et al. Mol. Cell. Biol. (2006) 26:5528.[Abstract/Free Full Text]
  24. de Hoog CL, Foster LJ, Mann M. Cell (2004) 117:649.[CrossRef][Web of Science][Medline]

Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?


This article has been cited by other articles:


Home page
 GeneticsHome page
I. Campos, J. A. Geiger, A. C. Santos, V. Carlos, and A. Jacinto
Genetic Screen in Drosophila melanogaster Uncovers a Novel Set of Genes Required for Embryonic Epithelial Repair
Genetics, January 1, 2010; 184(1): 129 - 140.
[Abstract] [Full Text] [PDF]

This Article
Right arrow Abstract Freely available
Right arrow FREE Full Text (PDF) Freely available
Right arrow All Versions of this Article:
19/11/1313    most recent
dxm100v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Heinze, M.
Right arrow Articles by Freund, C.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Heinze, M.
Right arrow Articles by Freund, C.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?