title: Structural conservation of the genes encoding CaT1, CaT2, and related cation channels.
abstract: We report here the genomic structures of the genes encoding human calcium transport proteins CaT1 and CaT2, which belong to a recently identified class of highly selective calcium entry channels. The mRNA for CaT1 was expressed more abundantly than that for CaT2 in three major tissues involved in transcellular calcium transport, namely intestine, kidney, and placenta, as determined by quantitative PCR. The genes encoding CaT1 and CaT2, ECAC2 and ECAC1, respectively, are completely conserved in terms of exon size in the coding regions. They also share similar intron-exon structures with the genes encoding the closely related, nonselective cation channels VR1, VRL-1, OTRPC4 (also known as VR-OAC, Trp12, and VRL-2), and a hypothetical protein, VRL-3. We conclude that ECAC2 and ECAC1, which encode calcium selective channels, share a common ancestral gene with the genes encoding the related nonselective cation channels.
authors.affiliation: Membrane Biology Program, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts, 02115, USA. jpeng@rics.bwh.harvard.edu
authors.forename: J B
authors.initials: JB
authors.lastname: Peng
authors.forename: E M
authors.initials: EM
authors.lastname: Brown
authors.forename: M A
authors.initials: MA
authors.lastname: Hediger
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D026923:Amino Acid Transport Systems, Basic; D000818:Animals; D015220:Calcium Channels / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D005091:Exons / Q000235:genetics; D005260:Female; D015723:Gene Library; D006801:Humans; D007421:Intestine, Small / Q000737:chemistry; D007668:Kidney / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009865:Oocytes / Q000737:chemistry / Q000378:metabolism; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy; D050916:TRPV Cation Channels; D014982:Xenopus laevis / Q000235:genetics
chemical_list: D026923:Amino Acid Transport Systems, Basic; D015220:Calcium Channels; C414177:SLC7A2 protein, human; D050916:TRPV Cation Channels; C492239:TRPV5 protein, human; C120776:TRPV6 channel; C422827:TRPV6 protein, human