Ultraviolet-induced cell death blocked by a selenoprotein from a human dermatotropic poxvirus.
Selenium, an essential trace element, is a component of prokaryotic and eukaryotic antioxidant proteins. A candidate selenoprotein homologous to glutathione peroxidase was deduced from the sequence of molluscum contagiosum, a poxvirus that causes persistent skin neoplasms in children and acquired immunodeficiency syndrome (AIDS) patients. Selenium was incorporated into this protein during biosynthesis, and a characteristic stem-loop structure near the end of the messenger RNA was required for alternative selenocysteine decoding of a potential UGA stop codon within the open reading frame. The selenoprotein protected human keratinocytes against cytotoxic effects of ultraviolet irradiation and hydrogen peroxide, providing a mechanism for a virus to defend itself against environmental stress.
Shisler
J L
JL
Laboratory of Viral Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 4 Center Drive, MSC 0445, Bethesda, MD 20892-0445, USA.
Senkevich
T G
TG
Berry
M J
MJ
Moss
B
B
D017209:Apoptosis; D001483:Base Sequence; D002460:Cell Line; D003062:Codon; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D015603:Keratinocytes / Q000166:cytology* / Q000187:drug effects; D008969:Molecular Sequence Data; D008977:Molluscum contagiosum virus / Q000235:genetics / Q000502:physiology*; D016366:Open Reading Frames; D017354:Point Mutation; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D012643:Selenium / Q000378:metabolism; D017279:Selenocysteine / Q000235:genetics; D051140:Selenoproteins; D014162:Transfection; D014466:Ultraviolet Rays; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D003062:Codon; D011506:Proteins; D051140:Selenoproteins; D014764:Viral Proteins; D017279:Selenocysteine; D006861:Hydrogen Peroxide; D005979:Glutathione Peroxidase; D012643:Selenium