Tiny T antigen: an autonomous polyomavirus T antigen amino-terminal domain.
Three mRNAs from the murine polyomavirus early region encode the three well-characterized tumor antigens. We report the existence of a fourth alternatively spliced mRNA which encodes a fourth tumor antigen, tiny T antigen, which comprises the amino-terminal domain common to all of the T antigens but is extended by six unique amino acid residues. The amount of tiny T antigen in infected cells is small because of its short half-life. Tiny T antigen stimulates the ATPase activity of Hsc70, most likely because of its DnaJ-like motif. The common amino-terminal domain may interface with chaperone complexes to assist the T antigens in carrying out their diverse functions of replication, transcription, and transformation in the appropriate cellular compartments.
Riley
M I
MI
Department of Biochemistry, University of Missouri-Columbia, 65121, USA. bcmriley@muccmail.missouri.edu
Yoo
W
W
Mda
N Y
NY
Folk
W R
WR
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000032:analysis / Q000235:genetics* / Q000502:physiology; D001483:Base Sequence; D019556:COS Cells; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D051379:Mice; D008969:Molecular Sequence Data; D011120:Polyomavirus / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis*
D000952:Antigens, Polyomavirus Transforming; D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger