yam8+, a Schizosaccharomyces pombe gene, is a potential homologue of the Saccharomyces cerevisiae MID1 gene encoding a stretch-activated Ca2+-permeable channel

The Saccharomyces cerevisiae MID1 gene encodes a stretch-activated Ca2+-permeable channel. In a protein database, we found a Schizosaccharomyces pombe gene whose predicted protein shows 26% identical and 62% similar to the Midi channel in amino acid sequence. cDNA derived from this gene, designated yam8(+), was isolated by reverse transcription-polymerase chain reaction (RT-PCR). Further analysis showed that the Yam8 protein consists of 486 amino acids and has 6 hydrophobic segments. The yam8(+) cDNA, placed under the S. cerevisiae TDH3 promoter, partially complemented the mating pheromone-induced death (mid) phenotype of the S. cerevisiae midi mutant. The expression of the yam8(+) cDNA in the midi mutant cells partially remediated the mid phenotype and resulted in a slight increase in Ca2+ uptake activity. These findings suggest that Yam8 is a potential homologue of Mid1. (C) 2000 Academic Press.