hnRNP G: Sequence and characterization of a glycosylated RNA-binding protein

The autoantlgen p43 is a nuclear protein initially identified with autoantibodles from dogs with a lupuslike syndrome. Here we show that p43 Is an RNAblnding protein, and identify it as hnRNP G, a previously described component of heterogeneous nuclear ribonucleoproteln complexes. We demonstrate that p43/hnRNP G Is glycosylated, and identify the modification as O-linked N-acetylglucosamine. A fulllength cDNA clone for hnRNP G has been isolated and sequenced, and the predicted amlno acid sequence for hnRNP G shows that It contains one RNP-consensus RNA binding domain (RBD) at the amlno terminus and a carboxyl domain rich In serines, arglnines and glyclnes. The RBD of human hnRNP G shows striking similarities with the RBDs of several plant RNA-blndlng proteins.