Cyclosporin A associated helicase-like protein facilitates the association of hepatitis C virus RNA polymerase with its cellular cyclophilin B

• Published in: PloS one 2011-04, Vol.6 (4), p.e18285
• Main Authors: Morohashi, Kengo, Sahara, Hiroeki, Watashi, Koichi, Iwabata, Kazuki, Sunoki, Takashi, Kuramochi, Kouji, Takakusagi, Kaori, Miyashita, Hiroki, Sato, Noriyuki, Tanabe, Atsushi, Shimotohno, Kunitada, Kobayashi, Susumu, Sakaguchi, Kengo, Sugawara, Fumio
• Format: Article
• Language: English
• Subjects: Adenosine triphosphatase; Adenosine Triphosphatases - biosynthesis; Adenosine Triphosphatases - chemistry; Adenosine Triphosphatases - physiology; Amino acids; Antigen presentation; Arabidopsis; Arabidopsis thaliana; ATPases; Biology; Cell Line, Tumor; Cloning; Cyclophilins - metabolism; Cyclosporin A; Cyclosporine - pharmacology; Cyclosporins; DNA helicase; DNA, Complementary - metabolism; DNA-directed RNA polymerase; DNA-Directed RNA Polymerases - metabolism; Gene expression; Genomes; Genomics; Glycoproteins; Hepacivirus - genetics; Hepatitis; Hepatitis C; Hepatitis C virus; Hepatology; Humans; Immunosuppressive agents; Immunosuppressive Agents - pharmacology; Laboratories; Lymphocytes B; Medicine; MicroRNAs; Peptide Library; Phage display; Phages; Physiological aspects; Plasmids - metabolism; Proteins; Recombinant Proteins - chemistry; Replication; Ribonucleic acid; RNA; RNA polymerase; RNA viruses; RNA, Viral - genetics; RNA, Viral - metabolism; Science; Surface Plasmon Resonance; Target recognition; Tissue Distribution; Transplantation; Veterinary colleges; Veterinary medicine; Viruses
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0018285

Cyclosporin A (CsA) is well known as an immunosuppressive drug useful for allogeneic transplantation. It has been reported that CsA inhibits hepatitis C virus (HCV) genome replication, which indicates that cellular targets of CsA regulate the viral replication. However, the regulation mechanisms of HCV replication governed by CsA target proteins have not been fully understood. Here we show a chemical biology approach that elucidates a novel mechanism of HCV replication. We developed a phage display screening to investigate compound-peptide interaction and identified a novel cellular target molecule of CsA. This protein, named CsA associated helicase-like protein (CAHL), possessed RNA-dependent ATPase activity that was negated by treatment with CsA. The downregulation of CAHL in the cells resulted in a decrease of HCV genome replication. CAHL formed a complex with HCV-derived RNA polymerase NS5B and host-derived cyclophilin B (CyPB), known as a cellular cofactor for HCV replication, to regulate NS5B-CyPB interaction. We found a cellular factor, CAHL, as CsA associated helicase-like protein, which would form trimer complex with CyPB and NS5B of HCV. The strategy using a chemical compound and identifying its target molecule by our phage display analysis is useful to reveal a novel mechanism underlying cellular and viral physiology.