A gene (pkt1) was isolated from the filamentous fungus Trichoderma reesei, which exhibits high homology with the yeast YPK1 and YKR2 (YPK2) genes. It contains a 2123-bp ORF that is interrupted by two introns, and it encodes a 662-amino-acid protein with a calculated M(r) of 72,820. During active growth, pkt1 is expressed as two mRNAs of 3.1 and 2.8 kb which differ in the 3' untranslated region due to the use of two different polyadenylation sites.