HnRNP G and Tra2beta: opposite effects on splicing matched by antagonism in RNA binding.

The hnRNP G family comprises three closely related proteins, hnRNP G, RBMY and hnRNP G-T. We showed previously that they interact with splicing activator proteins, particularly hTra2beta, and suggested that they were involved in regulating Tra2-dependent splicing. We show here that hnRNP G and hTra2beta have opposite effects upon the incorporation of several exons, both being able to act as either an activator or a repressor.

Effects of interferon alpha on the expression of p21cip1/waf1 and cell cycle distribution in carcinoid tumors.

Interferon alpha (IFN-alpha) has been shown to produce antitumor effects in 50-80% of carcinoid tumor patients and has demonstrated anti-proliferative effects in carcinoid tumor cells, but the mechanism is not well established. This study presents evidence that in a carcinoid tumor cell line, Bon1, IFN-alpha increases the expression of p21 and promotes nuclear translocation of endogenous p21. Furthermore, immunoprecipitation experiments demonstrated that p21 formed immuno-complexes with Stat1 and Stat2 in the nucleus of cells.