Developmental regulation of cmp1, a gene encoding a multidomain conidiospore surface protein of Trichoderma

Abstract

A gene encoding a developmentally regulated polypeptide of Trichoderma (strain ATCC 32173) was isolated, with the help of an antibody against a 62-kDa protein whose abundance strongly increases during photoinduced sporulation. The amino acid sequence deduced from this gene, cmp1 (conidial multidomain protein), is a 135-kDa polypeptide consisting of several domains. Although reminiscent of known structural modules, two of the domains may define novel families. The protein is apparently processed to give the 62-kDa species. Immunogold labeling electron microscopy localized the antigen to the membrane or inner wall layers. The mRNA is strongly up-regulated during sporulation. At least part of this regulation is likely to be conferred by several elements identified in the upstream region, with homology to elements recognized by fungal transcription factors for regulation by conidiation, light, and nitrogen stress. The developmental regulation, cell surface location, and modular structure suggest a function in cell-cell interactions, detection of the wall by the cell, or anchoring of the plasma membrane to the wall.