title: PKN-1, a homologue of mammalian PKN, is involved in the regulation of muscle contraction and force transmission in C. elegans.
abstract: To examine the in vivo functions of protein kinase N (PKN), one of the effectors of Rho small guanosine triphosphatases (GTPases), we used the nematode Caenorhabditis elegans as a genetic model system. We identified a C. elegans homologue (pkn-1) of mammalian PKN and confirmed direct binding to C. elegans Rho small GTPases. Using a green fluorescent protein reporter, we showed that pkn-1 is mainly expressed in various muscles and is localized at dense bodies and M lines. Overexpression of the PKN-1 kinase domain and loss-of-function mutations by genomic deletion of pkn-1 resulted in a loopy Unc phenotype, which has been reported in many mutants of neuronal genes. The results of mosaic analysis and body wall muscle-specific expression of the PKN-1 kinase domain suggests that this loopy phenotype is due to the expression of PKN-1 in body wall muscle. The genomic deletion of pkn-1 also showed a defect in force transmission. These results suggest that PKN-1 functions as a regulator of muscle contraction-relaxation and as a component of the force transmission mechanism.
authors.affiliation: Division of Signal Transduction, Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan. hkadota@emory.edu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Qadota
authors.forename: Takayuki
authors.initials: T
authors.lastname: Miyauchi
authors.forename: John F
authors.initials: JF
authors.lastname: Nahabedian
authors.forename: Jeffrey N
authors.initials: JN
authors.lastname: Stirman
authors.forename: Hang
authors.initials: H
authors.lastname: Lu
authors.forename: Mutsuki
authors.initials: M
authors.lastname: Amano
authors.forename: Guy M
authors.initials: GM
authors.lastname: Benian
authors.forename: Kozo
authors.initials: K
authors.lastname: Kaibuchi
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008322:Mammals / Q000235:genetics / Q000378:metabolism; D008957:Models, Genetic; D009119:Muscle Contraction / Q000235:genetics*; D009132:Muscles / Q000378:metabolism; D009154:Mutation; D009474:Neurons / Q000378:metabolism; D010641:Phenotype; D011485:Protein Binding / Q000235:genetics; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism*
chemical_list: D049452:Green Fluorescent Proteins; D011493:Protein Kinase C