Heterogeneous Nuclear Ribonucleoprotein L Like Protein (HNRPLL)

HNRNPLL is a master regulator of activation-induced alternative splicing in T cells. In particular, it alters splicing of CD45 (PTPRC), a tyrosine phosphatase essential for T-cell development and activation.

The HNRNPLL A isoform contains a third RRM domain and PTB, SH2, and WW interaction motifs. The HNRNPLL B isoform contains a coiled-coil region, a DNA binding domain, and 14-3-3 and PDZ interaction motifs. The HNRNPLL isoforms share 69% amino acid homology with HNRNPL and 46% homology with HNRNPI and ROD1 proteins. RT-PCR analysis detected expression of HNRNPLL transcripts A and B in bone marrow stromal cells only. Additional transcripts that differed in the 5-prime and 3-prime untranslated region were identified by database analysis.