The caspase-like Gpi8 subunit of Candida albicans GPI transamidase is a metal-dependent endopeptidase.

The caspase-like Gpi8 subunit of Candida albicans GPI transamidase is a metal-dependent endopeptidase. Biochem Biophys Res Commun. 2020 Feb 17;: Authors: Sah SK, Shefali S, Yadav A, Som P, Komath SS Abstract GPI anchored proteins (GPI-APs) act at the frontiers of cells, decoding environmental cues and determining host-pathogen interactions in several lower eukaryotes. They are also essential for viability in lower eukaryotes. The GPI biosynthetic pathway begins at the ER and follows a roughly linear pathway to generate the complete precursor (CP) glycolipid. The GPI transamidase (GPIT) transfers this glycolipid to the C-terminal end of newly translated proteins after removing their GPI attachment signal sequence (SS). The GPIT subunit that cleaves SS is Gpi8, a protein with a conserved Cys/His catalytic dyad typical of cysteine proteases. A CaGPI8 heterozygous mutant accumulates CPs and has reduced cell surface GPI-APs. Using a simple cell-free assay, we demonstrate that the heterozygous CaGPI8 strain has low endopeptidase activity as well. The revertant strain is restored in all these phenotypes. CaGpi8 is also shown to be a metalloenzyme, whose protease activity is sensitive to agents that modify Cys/His residues. PMID: 32081427 [PubMed - as supplied by publisher]
Source: Biochemical and Biophysical Research communications - Category: Biochemistry Authors: Tags: Biochem Biophys Res Commun Source Type: research