In vitro mutagenesis of the putative membrane-binding domain of polyomavirus middle-T antigen.

摘要: Polyomavirus middle-T antigen contains a contiguous sequence of 22 hydrophobic amino acids near the carboxyl terminus, which is putative membrane-binding domain protein. The DNA encoding this region was mutated to form series deletions, insertions, and substitutions called RX mutants. phenotypes these mutants fall into three groups based on transforming biochemical properties their encoded proteins. first group, with deletions outside but proximal domain, displayed an essentially wild-type phenotype. A second extensive within expressed species did not fractionate cellular membranes or associate pp60c-src were defective in ability transform. third group more subtle predicted alterations wild type for parameters investigated unable transform cultured rodent cells. These observations are consistent previous findings that membrane association plays important role transformation by that, whereas between necessary correlate transformation, it sufficient. comparison murine polyomavirus newly described hamster papovavirus revealed strong homology respective hydrophobic-domain acid sequences. This observed anchorage domains other model proteins, may imply reasons than simple association.