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RNA binding proteins-sexe
Elliot article2004
Déterminisme Sexuel
definition general


 RNA-binding motif protein, X chromosome
 Heterogenous nuclear ribonucleoprotein G
 RNA-binding motif protein, X chromosome retrogene
 hnRNP G

RBM has an ancient X-chromosome homologue called hnRNPG (also called RBMX). hnRNPG is expressed in all cells. Our hypothesis is that RBM might have become specialised to fulfil a special function in germ cells, while hnRNPG may play a somewhat similar role in other cells in the body. We are trying to using various approaches to address this function.

The University of Newcastle, Institute of Human Genetics

Autoimmune antibodies to hnRNPG protein in dogs with systemic lupus erythematosus: epitope mapping of the antigen.
J Autoimmun. 2002 May;18(3):221-9.
Soulard M, Della Valle V, Larsen CJ.

Centre de Biologie Veterinaire de l'Arche, 110 rue Jean Jaures, 92800, Puteaux, France.

We previously reported the presence of circulating autoantibodies to hnRNPG protein in dogs with systemic lupus erythematosus (Soulard et al. 1993, 1994). These antibodies appeared to be specifically limited to German shepherd dog species. In the present report, we have analysed the nature of the hnRNPG epitopes responsible for autoantibody specificity. By using a set of 11 dog sera selected for their strong reactivity to hnRNPG protein, we have found that these sera had the ability to recognize two epitopes: (1) within a stretch of 33 amino acids located around the central part of protein, that is readily detected by immunoblotting; (2) a N-terminal conformation of the protein close to the RNA binding domain (RBD), that is revealed by immunoprecipitation. Our data strongly support the notion that the dog autoimmune response against hnRNPG protein is antigen-driven.

A large set of proteins has been identified that binds to pre-mRNA.These proteins have been named hnRNP proteins (hnRNA is a historic name for RNA in the cell nucleus, much of which is pre-mRNA). Several different hnRNP-proteins bind to the same pre-mRNA immediately as the RNA is transcribed and an RNA-protein complex is formed.

Many of the hnRNP proteins share the same type of RNA binding domain. This concensus RNA binding domain can also be found in many other proteins that interact with mRNA, or other kinds of RNA. There are also other types of RNA binding domains found in other hnRNP proteins.

The hnRNP proteins presumably have several different functions, but these are not well known yet. It has been assumed that hnRNP proteins help package the pre-mRNA into functional complexes. For example, hnRNP proteins may be involved in presenting the pre-mRNA to the splicing machinery. It is known that hnRNP A1 protein can influence the choice of splice sites in pre-mRNA. Three hnRNP-proteins have been shown to be involved in the transport of mRNA to the cytoplasm. The hnRNP C protein contains a retention sequence that appears to prevent mRNA from being transported out of the nucleus and hnRNP A1 and hnRNP K each contain an export signal as part of their amino acid chain.

It is further possible that hnRNP proteins play a role also in the cytoplasm. The hnRNP A1 protein has been shown to accompany the mRNA into the cytoplasm and is present during translation.