MSP domain proteins show enhanced expression in male germ line cells.
Nematode sperm utilize a crawling motility based on polymerization--depolymerization of a nematode-specific cytoskeletal molecule-major sperm protein (MSP). While several proteins that interact with and regulate MSP filament formation have been identified using in vitro approaches, it is likely that additional molecules participate in vivo in the regulation of MSP cytoskeletal dynamics. By comparing EST data generated from an Ascaris suum testis germinal zone cDNA library with EST data from other tissue- and stage-specific A. suum cDNA libraries and with expression profile data from Caenorhabditis elegans, 42 genes were selected with exclusive or enhanced expression in male germ line cells. In addition to 11 protein kinases and seven protein phosphatases, 10 genes encoding proteins with protein-protein interaction domains were identified. These potential cytoskeletal modifiers included five novel MSP-domain proteins (As-MDPs). All five As-mdps were highly expressed in male germ line cells, but only As-mdp-2, 3 and 5 were transcribed exclusively in the testis. The prediction that As-MDP-1, 2 and 3 were cytosolic components and that As-MDP-4 and 5 were associated with the sperm cell membrane proteins was supported by the results of immunoblotting experiments. The 23 members of the MDP family of proteins from C. elegans were predicted to be transcribed in the testis. The findings provide additional candidates to the growing list of molecules that regulate MSP cytoskeletal dynamics.
The W Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA.
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Tarr
Alan L
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Scott
D000595:Amino Acid Sequence; D000818:Animals; D017165:Ascaris suum / Q000235:genetics* / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D019295:Computational Biology; D017124:Conserved Sequence; D018509:DNA, Helminth / Q000737:chemistry; D020224:Expressed Sequence Tags; D005260:Female; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D015801:Helminth Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013094:Spermatozoa / Q000378:metabolism; D013737:Testis / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; D018509:DNA, Helminth; D015801:Helminth Proteins; C050602:major sperm protein, nematode