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Regulation of CD45 alternative splicing by heterogeneous ribonucleoprotein, hnRNPLL.

ABSTRACT: The transition from naïve to activated T cells is marked by alternative splicing of pre-mRNA encoding the transmembrane phosphatase CD45. Using a short hairpin RNA interference screen, we identified heterogeneous ribonucleoprotein L-like (hnRNPLL) as a critical inducible regulator of CD45 alternative splicing. HnRNPLL was up-regulated in stimulated T cells, bound CD45 transcripts, and was both necessary and sufficient for CD45 alternative splicing. Depletion or overexpression of hnRNPLL in B and T cell lines and primary T cells resulted in reciprocal alteration of CD45RA and RO expression. Exon array analysis suggested that hnRNPLL acts as a global regulator of alternative splicing in activated T cells. Induction of hnRNPLL during hematopoietic cell activation and differentiation may allow cells to rapidly shift their transcriptomes to favor proliferation and inhibit cell death.

SUBMITTER: Oberdoerffer S

PROVIDER: S-EPMC2791692 | biostudies-literature | 2008 Aug

REPOSITORIES: biostudies-literature

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Regulation of CD45 alternative splicing by heterogeneous ribonucleoprotein, hnRNPLL.

Oberdoerffer Shalini S Moita Luis Ferreira LF Neems Daniel D Freitas Rui P RP Hacohen Nir N Rao Anjana A

Science (New York, N.Y.) 20080710 5889

The transition from naïve to activated T cells is marked by alternative splicing of pre-mRNA encoding the transmembrane phosphatase CD45. Using a short hairpin RNA interference screen, we identified heterogeneous ribonucleoprotein L-like (hnRNPLL) as a critical inducible regulator of CD45 alternative splicing. HnRNPLL was up-regulated in stimulated T cells, bound CD45 transcripts, and was both necessary and sufficient for CD45 alternative splicing. Depletion or overexpression of hnRNPLL in B and ...[more]

PMID: 18669861

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HnRNPLL is a global regulator of alternative splicing in activated T cells

Project description:HnRNPLL was identified as a critical regulator of CD45 alternative splicing in a lentiviral shRNA screen. RNAi-mediated depletion of hnRNPLL eliminated the activation-induced induced transition from the CD45RA to the CD45RO isoform. HnRNPLL is induced during the process of T cell activation, raising the possibility that it regulates a broad program of alternative splicing in activated T cells. To test this possibility and to identify additional potential targets of hnRNPLL, we performed exon array analysis on RNA isolated from five cellular conditions: 1) activated peripheral CD4+ T cells, 2) peripheral CD4+ T cells infected with a control shRNA directed against GFP, 3) peripheral CD4+ T infected with an shRNA directed against hnRNPLL, 4) naïve cord blood CD4+ T cells, and 5) cord blood CD4+ T cells that had been activated with anti-CD3 and anti-CD28 for 24 hours. The RNA was hybridized to Affymetrix human exon arrays and the hybridization signals were analyzed with XRAYTM software (Biotique). Using stringent filters for non-expressed probesets, we identified 132 genes that showed significant alternative exon usage (p<0.01) in response to hnRNPLL knockdown, but not in response to shGFP infection. Of these 132 genes, 36 also showed significant alternative exon usage in response to activation of cord blood cells, which results in an approximate 5-fold increase in hnRNPLL expression. We thus conclude that induction of hnRNPLL represents a mechanism by which cells can rapidly shift their transcriptomes during the process of T cell activation. This SuperSeries is composed of the SubSeries listed below.

2008-06-20 | GSE11834 | GEO

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