Screening And Preliminary Identification Of Host Cellular Proteins Binding With Sars-CoV S And N Protein

SARS-CoV is a newly discovered coronavirus which was identified as the etiological agent of severe acute respiratory syndrome (SARS). Four structural proteins have been presently identified in SARS-CoV, including spike (S) protein, membrane (M) protein, nucleocapsid (N) protein and envelope (E) protein. Previous studies showed that S and N proteins play key roles in SARS-CoV replication and manipulation of the host cells. S protein plays vital roles in determining tissue tropism, viral entry as well as cell-to-cell spread, and also induces host apoptosis. Angiotensin-converting enzyme 2 (ACE2) was identified as the functional receptor for SARS-CoV. CD209 and CD209L might serve as alternative receptor. Cleavage of S protein by endosomal protease cathepsin L during entry can facilitate virus entry process. Recent reports demonstrated that SARS-CoV N protein principally localized to the cytoplasm, also to the nucleolus. N protein might play roles in the formation of ribonucleoprotein (RNP) complex, the replication of genomic RNA, the transcription and translation of subgenomic RNAs (sgRNA). In addition, N protein might inhibit host cell proliferation or delay cell growth, possibly by disrupting cytokinesis. To date, some host cellular proteins interacted with N protein had been identified including hnRNP A1, 14-3-3 proteins, cyclin-CDK complex, small ubiquitin-related modifier(SUMO) and cyclophilin A. By the knowledge of genomes, proteomes and cell signal transduction, the known interaction between these proteins and S or N protein is just the tip of the iceberg and unlikely to account for all functions of S...