Structural and functional characterization of herpes simplex virus 1 immediate-early protein infected-cell protein 22.
Of the five HSV1 immediate-early proteins, infected-cell protein 22 (ICP22), the product of the Us1 gene, is a member whose function is less understood. In order to promote better understanding of the role of ICP22 in viral replication, mutation and fluorescence techniques were used to investigate the biochemical relationship between ICP22's structure and nuclear localization, and the CAT assay was used to analyze the relationship between ICP22's structure and its transcriptional repression. The results of these experiments implied (i) ICP22 is localized to small dense nuclear bodies and is paired with the SC-35 domain in the nucleus, (ii) ICP22 localization in a punctate state requires completion of the main sequence which includes the 1-320th amino acids, (iii) a conservative mutation in the nucleotidylylation site is important for its nuclear localization and transcriptional repression, and (4) despite possessing the same amino acid sequence as the ICP22 carboxyl-terminal, Us1.5 was distinct from ICP22 in location and function.
Cun
Wei
W
Institute of Medical Biology, Chinese Academy of Medical Sciences and Peking Union Medical College, Kunming 650118, P.R. China.
Hong
Min
M
Liu
Long-Ding
LD
Dong
Chen-Hong
CH
Luo
Jie
J
Li
Qi-Han
QH
D000818:Animals; D016466:CHO Cells; D002467:Cell Nucleus / Q000502:physiology; D002522:Chlorocebus aethiops; D006224:Cricetinae; D003412:Cricetulus; D018259:Herpesvirus 1, Human / Q000235:genetics*; D017874:Immediate-Early Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D009713:Nucleotidyltransferases / Q000235:genetics; D021381:Protein Transport / Q000502:physiology; D012097:Repressor Proteins / Q000502:physiology; D014162:Transfection; D014709:Vero Cells; D014764:Viral Proteins / Q000502:physiology; D054334:Viral Regulatory and Accessory Proteins
C057294:ICP22 protein, human herpesvirus 1; D017874:Immediate-Early Proteins; D012097:Repressor Proteins; D014764:Viral Proteins; D054334:Viral Regulatory and Accessory Proteins; D009713:Nucleotidyltransferases