hnRNP G Products

Heterogeneous nuclear ribonucleoproteins (hnRNPs) constitute a set of polypeptides that contribute to mRNA transcription, pre-mRNA processing as well as mature mRNA transport to the cytoplasm and translation. They also bind heterogeneous nuclear RNA (hnRNA), which are the transcripts produced by RNA polymerase II. There are approximately 20 known hnRNP proteins, and their complexes are the major constituents of the spliceosome. The majority of hnRNP proteins components are localized to the nucleus; however some shuttle between the nucleus and the cytoplasm. hnRNP G is a glycoprotein, which was originally identified as an autoantigen from German shepherd dogs with lupus-like syndrome. The gene encoding hnRNP G is located on chromosome Xq26 and is ubiquitously expressed. It contains one RNP-consensus RNA binding domain (RBD) and is related to RBMY, which is involved in spermatogenesis, and hnRNP G-T, which is a testis specific protein. All three proteins interact with Tra2b and therefore, are involved in pre-mRNA splicing.