The Neurospora peptide:N-glycanase ortholog PNG1 is essential for cell polarity despite its lack of enzymatic activity.

ABSTRACT: Secretory proteins are subjected to a stringent endoplasmic reticulum-based quality control system that distinguishes aberrant from correctly folded proteins. The cytoplasmic peptide:N-glycanase cleaves oligosaccharides from misfolded glycoproteins and prepares them for degradation by the 26 S proteasome. In contrast to abundant in vitro data on its enzymatic function, the in vivo relevance of peptide:N-glycanase activity remains unclear. Here we show that the PNG1 ortholog from the filamentous ascomycete Neurospora crassa is an essential protein, and its deletion results in strong polarity defects. PNG1 and its predicted binding partner RAD23 have distinct functions in N. crassa and are involved in cell wall integrity and DNA repair, respectively. Moreover, wild type PNG1 has substitution

SUBMITTER: Maerz S 

PROVIDER: S-EPMC2807290 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature