Selectivity of the ubiquitin pathway for oxidatively modified proteins: relevance to protein precipitation diseases

Abstract
SPECIFIC AIMSThere is now consensus that: 1) the accumulation of oxidatively modified proteins is cytotoxic and causally related to several age-related diseases including age-related cataracts and other amyloid diseases; and 2) that proteolytic pathways provide a quality control mechanism to limit accumulation of modified proteins. Although many researchers assume that the ubiquitin proteasome pathway (UPP) is involved in recognition and proteolytic removal of oxidatively modified proteins that are produced upon cellular stress, there has been no direct evidence to support this hypothesis. This research tested the hypothesis that the UPP is involved in the selective targeting of oxidatively damaged proteins as well as in maintenance of cellular viability upon oxidative challenge.PRINCIPAL FINDINGS1. Oxidatively modified proteins are preferred substrates for ubiquitinationUsing K6W-Ub, we directly tested the hypothesis that as compared with nonoxidatively modified proteins, oxidatively modified proteins ar...
Funding Information
  • National Institutes of Health (EY13250, EY14183, EY11717)
  • U.S. Department of Agriculture (58‐1950‐9‐001, 950‐51000‐060‐01A)