title: Molecular cloning and evolutionary analysis of the calcium-modulated contractile protein, centrin, in green algae and land plants.
abstract: Centrin (= caltractin) is a ubiquitous, cytoskeletal protein which is a member of the EF-hand superfamily of calcium-binding proteins. A centrin-coding cDNA was isolated and characterized from the prasinophyte green alga Scherffelia dubia. Centrin PCR amplification primers were used to isolate partial, homologous cDNA sequences from the green algae Tetraselmis striata and Spermatozopsis similis. Annealing analyses suggested that centrin is a single-copy-coding region in T. striata and S. similis and other green algae studied. Centrin-coding regions from S. dubia, S. similis and T. striata encode four colinear EF-hand domains which putatively bind calcium. Phylogenetic analyses, including homologous sequences from Chlamydomonas reinhardtii and the land plant Atriplex nummularia, demonstrate that the domains of centrins are congruent and arose from the two-fold duplication of an ancestral EF hand with Domains 1+3 and Domains 2+4 clustering. The domains of centrins are also congruent with those of calmodulins demonstrating that, like calmodulin, centrin is an ancient protein which arose within the ancestor of all eukaryotes via gene duplication. Phylogenetic relationships inferred from centrin-coding region comparisons mirror results of small subunit ribosomal RNA sequence analyses suggesting that centrin-coding regions are useful evolutionary markers within the green algae.
authors.affiliation: Universität zu Köln, Botanisches Institut, Lehrstuhl I, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Bhattacharya
authors.forename: J
authors.initials: J
authors.lastname: Steinkötter
authors.forename: M
authors.initials: M
authors.lastname: Melkonian
mesh_terms: D000595:Amino Acid Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics*; D002147:Calmodulin / Q000235:genetics; D018797:Cell Cycle Proteins; D000460:Chlorophyta / Q000235:genetics*; D002868:Chromosomal Proteins, Non-Histone; D003285:Contractile Proteins / Q000235:genetics*; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary; D005656:Fungal Proteins / Q000235:genetics; D017343:Genes, Plant; D008969:Molecular Sequence Data; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: C083769:CDC31 protein, S cerevisiae; D002135:Calcium-Binding Proteins; D002147:Calmodulin; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D003285:Contractile Proteins; D017931:DNA Primers; D018076:DNA, Complementary; D005656:Fungal Proteins; D010940:Plant Proteins; D029701:Saccharomyces cerevisiae Proteins; C056608:caltractin