title: A calmodulin like EF hand protein positively regulates oxalate decarboxylase expression by interacting with E-box elements of the promoter.
abstract: Oxalate decarboxylase (OXDC) enzyme has immense biotechnological applications due to its ability to decompose anti-nutrient oxalic acid. Flammulina velutipes, an edible wood rotting fungus responds to oxalic acid by induction of OXDC to maintain steady levels of pH and oxalate anions outside the fungal hyphae. Here, we report that upon oxalic acid induction, a calmodulin (CaM) like protein-FvCaMLP, interacts with the OXDC promoter to regulate its expression. Electrophoretic mobility shift assay showed that FvCamlp specifically binds to two non-canonical E-box elements (AACGTG) in the OXDC promoter. Moreover, substitutions of amino acids in the EF hand motifs resulted in loss of DNA binding ability of FvCamlp. F. velutipes mycelia treated with synthetic siRNAs designed against FvCaMLP showed significant reduction in FvCaMLP as well as OXDC transcript pointing towards positive nature of the regulation. FvCaMLP is different from other known EF hand proteins. It shows sequence similarity to both CaMs and myosin regulatory light chain (Cdc4), but has properties typical of a calmodulin, like binding of (45)Ca(2+), heat stability and Ca(2+) dependent electrophoretic shift. Hence, FvCaMLP can be considered a new addition to the category of unconventional Ca(2+) binding transcriptional regulators.
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Ayushi
authors.initials: A
authors.lastname: Kamthan
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Mohan
authors.initials: M
authors.lastname: Kamthan
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Avinash
authors.initials: A
authors.lastname: Kumar
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Pratima
authors.initials: P
authors.lastname: Sharma
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Sekhu
authors.initials: S
authors.lastname: Ansari
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Sarjeet Singh
authors.initials: SS
authors.lastname: Thakur
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Abira
authors.initials: A
authors.lastname: Chaudhuri
authors.affiliation: National Institute of Plant Genome Research, New Delhi, India.
authors.forename: Asis
authors.initials: A
authors.lastname: Datta
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002262:Carboxy-Lyases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D020832:EF Hand Motifs / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D055393:Flammulina / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D025301:Hyphae / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D019815:Oxalic Acid / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D002147:Calmodulin; D005656:Fungal Proteins; D012333:RNA, Messenger; D011994:Recombinant Proteins; D019815:Oxalic Acid; D002262:Carboxy-Lyases; C021915:oxalate decarboxylase; D002118:Calcium