Lysine-87 is a functionally important residue in human prothymosin alpha.
Human prothymosin alpha mutants were generated with the aid of random mutagenesis and screened for their ability to inhibit yeast Saccharomyces cerevisiae cell growth. Conversion of Lys-87 to Glu resulted in an inactivated prothymosin alpha mutant, which lost the ability of the wild-type protein to block yeast cell growth. We propose that prothymosin alpha may possess a bipartite rather than monopartite nuclear localization signal, which includes Lys-87, and that the above mutation destroys one part of the nuclear localization signal, thus preventing efficient nuclear uptake of prothymosin alpha.
Rubtsov
Y
Y
Belozersky Institute of Physico-Chemical Biology, Moscow State University, Russian Federation.
Vartapetian
A
A
D000595:Amino Acid Sequence; D002467:Cell Nucleus / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000737:chemistry*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010957:Plasmids; D017354:Point Mutation; D011498:Protein Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000254:growth & development; D013947:Thymosin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D014170:Transformation, Genetic
D011498:Protein Precursors; C040782:prothymosin alpha; D013947:Thymosin; D008239:Lysine