Pleiotropic roles of a calcium binding protein, calumenin in Caenorhabditis elegans

Abstract

Calumenin is calcium binding protein containing EF hand motif. It is localized in the ER. Perturbed level of calumenin is casually associated with several diseases such as cancer, atherosclerosis and drug resistance. However, the physiological role of calumenin is largely unknown. Caenorhabditis elegans calumenin shows 45% identity and 62% similarity with its human counterpart. We have characterized a deletion mutant of C. elegans calumenin, calu-1(tm1783), in which approximately 200bp of 5 upstream region followed by the initial two exons are deleted. Western blot and RT-PCR showed that it is a loss-of-function mutant. Around 37% of the mutants showed bursted vulva phenotype during the transition from L4 to adult molt. Furthermore, mutants exhibit pleiotropic defects such as decreased brood size, sluggish locomotion, small body size, slow growth, suggesting calumenin is important for normal development in C. elegans. We found that, in male, calumenin has strong expression in pharynx, spicules.