STUDYING THE FUNCTIONAL INTERACTION BETWEEN SRSF1 AND PIAS1 ON THE REGULATION OF SUMO CONJUGATION

MAMMI, PABLO; GAIOLI, NICOLAS; SREBROW, ANABELLA

Paraná

Congreso; LIV Reunion Anual de la Sociedad Argentina de Bioquimica y Biologia Molecular; 2018

Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular

The RNA­-binding protein SRSF1, a member of the SR family of proteins, has been deeply characterized as a regulator of the splicing process. After the discovery of its involvement in a wide variety of functions at several levels of gene expression regulation, this factor has become a paradigm of multitasking protein. Few years ago, our laboratory has revealed that SRSF1 modulates SUMO conjugation to different target proteins both in cultured cells and in vitro, displaying characteristics of a SUMO E3 ligase. A well­-known member of this latter group is PIAS1, with which we have shown SRSF1 interacts. As part of the characterization of the role of SRSF1 in the SUMO conjugation pathway, we have generated a series of SRSF1 mutants, which not only display differential RNA binding capacities but also differential SUMOylation enhancing effects. Recently, we have observed that over­-expression of wild type SRSF1 in HEK 293T cells, enhances PIAS1 protein levels. Working with the above­-mentioned SRSF1 mutants, we are currently exploring whether the regulation of SUMO conjugation is due to the observed changes on PIAS1 levels. Furthermore, we expect to unravel whether SRSF1 affects PIAS1 by controlling its mRNA or protein stability and/or its translation rate.