title: Identification of critical amino acid residues and functional conservation of the Neurospora crassa and Rattus norvegicus orthologues of neuronal calcium sensor-1.
abstract: Neuronal calcium sensor-1 (NCS-1) is a member of neuronal calcium sensor family of proteins consisting of an amino terminal myristoylation domain and four conserved calcium (Ca2+) binding EF-hand domains. We performed site-directed mutational analysis of three key amino acid residues that are glycine in the conserved site for the N-terminal myristoylation, a conserved glutamic acid residue responsible for Ca2+binding in the third EF-hand (EF3), and an unusual non-conserved amino acid arginine at position 175 in the Neurospora crassa NCS-1. The N. crassa strains possessing the ncs-1 mutant allele of these three amino acid residues showed impairment in functions ranging from growth, Ca2+stress tolerance, and ultraviolet survival. In addition, heterologous expression of the NCS-1 from Rattus norvegicus in N. crassa confirmed its interspecies functional conservation. Moreover, functions of glutamic acid at position 120, the first Ca2+binding residue among all the EF-hands of the R. norvegicus NCS-1 was found conserved. Thus, we identified three critical amino acid residues of N. crassa NCS-1, and demonstrated its functional conservation across species using the orthologue from R. norvegicus.
authors: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India.
authors: Dibakar
authors: D
authors: Gohain
authors: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India.
authors: Rekha
authors: R
authors: Deka
authors: Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, 781 039, India. ranjantamuli@iitg.ernet.in.
authors: Ranjan
authors: R
authors: Tamuli
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D051580:Neuronal Calcium-Sensor Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009479:Neuropeptides / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D009492:Neurospora crassa / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D051381:Rats; D017386:Sequence Homology, Amino Acid; D014466:Ultraviolet Rays
chemical_list: D005656:Fungal Proteins; D051580:Neuronal Calcium-Sensor Proteins; D009479:Neuropeptides; C101464:frequenin calcium sensor proteins; D002118:Calcium
keywords: Calcium binding; EF-hand domain; Heterologous expression; N-terminal myristoylation; Neuronal calcium sensor-1; Neurospora crassa; Rattus norvegicus; Site- directed mutagenesis; Ultraviolet survival