Functional and structural studies of three human regulatory proteins: Fez1, Ki-1/57 and NSAP1 (hnRNP-Q)

Abstract

We want to study the function and structure of three human regulatory proteins which are involved in human diseases. About the protein NSAP1 (hnRNP-Q) it is known that it is a RNA binding protein and that it is possibly involved in pre-mRNA - splicing - and the degradation of mRNAs, which encode oncoproteins. Structurally this protein was not studied yet, but it is known that it is composed of one - acid domain, three RRM domains (RNA recognition motifs, which bind RNA) and one RG-box, which a target of arginine methylation. The functions and structures of the other two proteins, Ki-1/57 and Fez1, are still not known. In previous studies we identified a series of proteins that are involved in cellular signalization processes and the regulation of transcription, that interact with Fez1 or Ki-1/57. This suggests that both proteins are involved in this cellular context, although the association to other cellular process cannot be ruled out. In this project we intend to study the structure of the mentioned proteins or of their individual domains by spectroscopic methods and protein cristallography. We also will study the function of these proteins using several modern molecular biology techniques, including among others: gene silencing (iRNA method), identification of post-translational modifications and interacting proteins in vitro (mass spectrometry) as well as in vitro (yeast two-hybrid system), SELEX (Systematic evolution of ligands by exponential enrichment) to identify interacting RNA target sequences. (AU)