title: Molecular evolution of the multiple calmodulin-like cal genes in C. elegans and in nematodes.
abstract: Calmodulin (CaM) is a major EF hand containing intracellular calcium receptor in animals and plants; however, eukaryotes also express a number of related CaM-like proteins. We have previously characterized an embryonic phenotype of the single Caenorhabditis elegans CaM gene cmd-1, reported no visible RNAi phenotype for the four related cal-1 to cal-4 genes and started tissue-specific expression analyses of these proteins. In the present study, we analyzed evolutionary aspects of the previously reported CAL-1 to CAL-4 proteins, along with the four new CAL-5 to CAL-8 sequences retrieved from the worm database. Phylogenetic analyses suggest that all C. elegans CAL proteins arose from a CaM ancestor through repeated gene duplications, fusions and sequence divergence. The same holds, also, for the variable N-terminal extensions of the CAL-1 to CAL-4 proteins, which have evolved from the CaM-like core domain. We found 97 CAL homologs in different nematode clades and also detected two CAL-7-related sequences outside the nematodes. Moreover, the C. elegans-specific cal-6 gene, representing the most CaM-related sequence found in nematodes so far, harbours many deletions, insertions and sequence substitutions and is predicted, therefore, to be non-functional. These analyses provide an insight into a complex and dynamic origin of the multiple CAL genes in C. elegans and in nematodes and represent also a basis for further functional studies of these CaM-related sequences in nematodes.
authors: SEMBID, s.r.o.-Research Centre of Innovative Therapeutic Approaches in Molecular Medicine, Magnezitarska 2/C, 04013, Kosice, Slovakia. sembid.pp@gmail.com.
authors: Anton
authors: 0000-0001-6633-4343
authors: A
authors: Karabinos
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D002147:Calmodulin / Q000737:chemistry / Q000235:genetics*; D020832:EF Hand Motifs; D019143:Evolution, Molecular; D009348:Nematoda / Q000235:genetics*; D010802:Phylogeny
chemical_list: D002147:Calmodulin
keywords: C. elegans; Calmodulin-like proteins; Molecular evolution; Nematode; RNA interference