Identification and characterization of a novel polycystin family member, polycystin-L2, in mouse and human: sequence, expression, alternative splicing, and chromosomal localization.
Polycystins-1, -2, -L, and -REJ are the four known members of the polycystin family of proteins. In this study, we describe a fifth member of the family, polycystin-L2, encoded by PKD2L2 in human and Pkd2l2 in mouse. Full-length cDNA sequences for both mouse and human polycystin-L2 were obtained from testis cDNA. Sequence analysis predicts that the mouse and human polycystin-L2 proteins consist of 621 and 624 amino acid residues, respectively. Polycystin-L2 has significant homology with polycystins-L and -2, with similarities of 58 and 59%, respectively. Both human and murine polycystin-L2 proteins are predicted to have seven putative transmembrane (TM) domains, and, by comparison with transient receptor potential channels, the six carboxyl-terminal TM domains are likely to constitute an ion channel subunit. Northern blot analysis indicated that mouse Pkd2l2 has an abundant approximately 2.5-kb transcript in testis and an approximately 2.2-kb transcript in heart. RT-PCR analysis showed that the full-length transcript is expressed in human brain, kidney, testis, and HepG2 cells, and there are three alternatively spliced variants that were differentially expressed. PKD2L2 consists of 17 exons spanning approximately 50 kb of genomic DNA. PKD2L2 was mapped to human chromosome 5q31 and Pkd2l2 to mouse chromosome 18 in band C.
Guo
L
L
Renal Division, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115, USA.
Schreiber
T H
TH
Weremowicz
S
S
Morton
C C
CC
Lee
C
C
Zhou
J
J
D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D015220:Calcium Channels; D002460:Cell Line; D002874:Chromosome Mapping; D002895:Chromosomes, Human, Pair 5 / Q000235:genetics*; D003001:Cloning, Molecular; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007668:Kidney / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013737:Testis / Q000378:metabolism
D015220:Calcium Channels; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C511304:PKD2L2 protein, human; C511305:Pkd2l2 protein, mouse; D012333:RNA, Messenger