title: The calmodulin gene in Neurospora crassa is required for normal vegetative growth, ultraviolet survival, and sexual development.
abstract: We isolated a Neurospora crassa mutant of the calmodulin (cmd) gene using repeat-induced point mutation and studied its phenotypes. The cmdRIPmutant showed a defect in growth, reduced aerial hyphae, decreased carotenoid accumulation, a severe reduction in viability upon ultraviolet (UV) irradiation, and a fertility defect. Moreover, meiotic silencing of the cmd gene resulted in a barren phenotype. In addition, we also performed site-directed mutational analysis of the calcium/calmodulin-dependent kinase-2 (Ca2+/CaMK-2), a target of the CaM protein encoded by the cmd gene. The camk-2S247Aand the camk-2T267Amutants in a homozygous cross, or in a cross with a Δcamk-2 mutant, displayed an intermediate phenotype, suggesting that serine 247 and threonine 267 phosphorylation sites of the Ca2+/CaMK-2 are essential for full fertility in N. crassa. Therefore, CaM in N. crassa is required for normal vegetative growth, UV survival, and sexual development. Additionally, serine 247 and threonine 267 phosphorylation sites are important for the Ca2+/CaMK-2 function.
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039, India.
authors.forename: Vijya
authors.initials: V
authors.lastname: Laxmi
authors.affiliation: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, Assam, 781 039, India. ranjantamuli@iitg.ernet.in.
authors.forename: Ranjan
authors.initials: R
authors.lastname: Tamuli
mesh_terms: D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2 / Q000235:genetics; D002147:Calmodulin / Q000235:genetics*; D025301:Hyphae / Q000254:growth & development; D050296:Microbial Viability / Q000528:radiation effects; D016297:Mutagenesis, Site-Directed; D009492:Neurospora crassa / Q000235:genetics* / Q000254:growth & development / Q000528:radiation effects; D010641:Phenotype; D014466:Ultraviolet Rays
chemical_list: D002147:Calmodulin; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2
keywords: Calcium signaling; Calcium/calmodulin-dependent protein kinases; Calmodulin; Meiotic silencing; Neurospora crassa; Repeat-induced point mutation