Proteomic Analysis of Proteins Associated with Splicing Factor-2 Associated Protein p32 Revealed its Possible Involvement in Human Ribosome Biogenesis

Abstract

Splicing factor-2 associated protein p32 (SF2p32) interacts with many cellular and viral proteins such as ASF/SF2, human immunodeficiency virus (HIV) Rev and Tat proteins etc. Among those, the interaction with HIV Rev is thought to be responsible for inhibition of the splicing of HIV transcripts, resulting in infection and production of progeny virions in human cells. Because of the ability of SF2p32 to interact with many proteins, it is believed to have many functions in the cell; however, its physiological role remains unclear. Our previous proteomic analysis identified SF2p32 as a component of the protein complexes associated with fibrillarin, which is the nucleolar antigen of the autoimmune disease scleroderma and is involved in early stage of ribosome biogenesis. In this study, we examined a possible involvement of SF2p32 in ribosome biogenesis by using proteomic methodologies.