title: The single pore residue Asp523 in PKD2L1 determines Ca2+ permeation of the PKD1L3/PKD2L1 complex.
abstract: The polycystic kidney disease 1-like 3 (PKD1L3)-polycystic kidney disease 2-like 1 (PKD2L1) complex functions as a Ca(2+)-permeable, non-selective cation channel that is activated by acid and its subsequent removal; this is called an off-response. In this study, we identified a single aspartic residue in PKD2L1 that is responsible for the Ca(2+) permeation of the PKD1L3/PKD2L1 complex. Calcium imaging analysis using point mutants of negatively charged amino acids present in the putative pore regions of PKD1L3 and PKD2L1 revealed that neutralization of the aspartic residue in PKD2L1 (D523N), which is conserved among PKD2 family members, abolished Ca(2+) permeation, despite robust cell surface expression. In contrast, neutralization of the other negatively charged residues of PKD1L3 (D2049N and E2072Q) and PKD2L1 (D525N and D530N) as well as substitution of Asp(523) with a glutamate residue (D523E) had little effect on Ca(2+) permeation properties. These results demonstrate that Asp(523) in PKD2L1 is a key determinant of Ca(2+) permeation into the PKD1L3/PKD2L1 complex and that PKD2L1 contributes to forming the pore of the PKD1L3/PKD2L1 channel.
authors.affiliation: Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan.
authors.forename: Chisato
authors.initials: C
authors.lastname: Fujimoto
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Ishimaru
authors.forename: Yuka
authors.initials: Y
authors.lastname: Katano
authors.forename: Takumi
authors.initials: T
authors.lastname: Misaka
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Yamasoba
authors.forename: Tomiko
authors.initials: T
authors.lastname: Asakura
authors.forename: Keiko
authors.initials: K
authors.lastname: Abe
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001224:Aspartic Acid / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002463:Cell Membrane Permeability / Q000235:genetics*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D017354:Point Mutation; D017434:Protein Structure, Tertiary; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism*; D050396:TRPP Cation Channels / Q000378:metabolism*
chemical_list: D015220:Calcium Channels; C512453:PKD1L3 protein, mouse; C486487:Pkd2l1 protein, mouse; D011956:Receptors, Cell Surface; D050396:TRPP Cation Channels; D001224:Aspartic Acid; D002118:Calcium