Ribosomal protein S5 interacts with the internal ribosomal entry site of hepatitis C virus.
Translational initiation of hepatitis C virus (HCV) genome RNA occurs via its highly structured 5' noncoding region called the internal ribosome entry site (IRES). Recent studies indicate that HCV IRES and 40 S ribosomal subunit form a stable binary complex that is believed to be important for the subsequent assembly of the 48 S initiation complex. Ribosomal protein (rp) S9 has been suggested as the prime candidate protein for binding of the HCV IRES to the 40 S subunit. RpS9 has a molecular mass of approximately 25 kDa in UV cross-linking experiments. In the present study, we examined the approximately 25-kDa proteins of the 40 S ribosome that form complexes with the HCV IRES upon UV cross-linking. Immunoprecipitation with specific antibodies against two 25-kDa 40 S proteins, rpS5 and rpS9, clearly identified rpS5 as the protein bound to the IRES. Thus, our results support rpS5 as the critical element in positioning the HCV RNA on the 40 S ribosomal subunit during translation initiation.
Fukushi
S
S
Research and Development Center, BioMedical Laboratories, 1361-1 Matoba, Kawagoe, Saitama 350-1101, Japan. sfukushi@alk.co.jp
Okada
M
M
Stahl
J
J
Kageyama
T
T
Hoshino
F B
FB
Katayama
K
K
D020121:5' Untranslated Regions / Q000235:genetics*; D000595:Amino Acid Sequence; D001665:Binding Sites; D016174:Hepacivirus / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010442:Peptide Chain Initiation, Translational; D012367:RNA, Viral / Q000235:genetics*; D000091243:Ribosomal Protein S9; D012269:Ribosomal Proteins / Q000737:chemistry / Q000378:metabolism*; D012270:Ribosomes / Q000378:metabolism* / Q000821:virology*
D020121:5' Untranslated Regions; D012367:RNA, Viral; D000091243:Ribosomal Protein S9; D012269:Ribosomal Proteins; C041308:ribosomal protein S40; C030831:ribosomal protein S5