Cloning and expression of a putative type II metacaspase from Schizophyllum commune

Abstract

Metacaspases are cysteine proteases similar in sequence to caspases. In Saccharomyces cerevisiae they undergo caspase‐like processing and have proteolytic activity. Experiments in several organisms have shown that metacaspases function similarly to caspases and are involved in apoptosis, although some work suggests that they are non‐apoptotic proteases. Type I metacaspases have a proline rich domain at the N‐terminus and Type II metacapases contain an linker region between the p20 and p10 subunits, but lack the proline rich domain. Five metacaspase genes are present in the genome of S. commune and one of them, scp1‐a type I, has been cloned and expressed in E.coli. In this report a type II metacaspase from S. commune, scp3, was successfully cloned into pQE‐80. Due to a mis‐predicted intron/exon boundary in the genome there is a deletion of a 74bp sequence, 640bp after the start codon in the cloned open reading frame. Next, scp3‐pQE‐80 was successfully expressed in E. coli strain M15[pREP4] and purified using Ni+ affinity chromatography. Research supported by Merck/AAAS.