Molecular cloning and characterization of human podocalyxin-like protein. Orthologous relationship to rabbit PCLP1 and rat podocalyxin.
Human renal cortex and heart cDNA libraries were screened for a human homolog of rabbit PCLP1 using the rabbit PCLP1 cDNA as a probe. Clones spanning 5869 base pairs with an open reading frame coding for a 528-amino acid peptide were obtained. The putative peptide contains a potential signal peptide and a single membrane-spanning region. The extracellular domain contains multiple potential sites for N- and O-linked glycosylation and 4 cysteines for potential disulfide bonding similar to rabbit PCLP1. On Northern blot a major transcript is seen at 5.9 kilobases. Antibodies to this protein show a doublet at 160/165 kDa on Western blots of human glomerular extract and a pattern of intense glomerular staining and vascular endothelial staining on immunofluorescence of human kidney sections. Comparison of the rabbit and human peptide sequences shows a high degree of identity in the transmembrane and intracellular domains (96%) with a lower degree of identity in the extracellular domain (36%). An antibody to the intracellular domain reacted across species (human, rabbit, and rat) and recognized both rabbit PCLP1 and rat podocalyxin. An interspecies Southern blot probed with a cDNA coding for the intracellular domain showed strong hybridization to all vertebrates tested in a pattern suggesting a single copy gene. We conclude that this cDNA and putative peptide represent the human homolog of rabbit PCLP1 and rat podocalyxin.
Kershaw
D B
DB
Department of Pediatrics, University of Michigan, Ann Arbor, Michigan 48109, USA.
Beck
S G
SG
Wharram
B L
BL
Wiggins
J E
JE
Goyal
M
M
Thomas
P E
PE
Wiggins
R C
RC
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017124:Conserved Sequence; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D011817:Rabbits; D051381:Rats; D012795:Sialoglycoproteins / Q000737:chemistry / Q000235:genetics*
D008562:Membrane Glycoproteins; D012795:Sialoglycoproteins; C001643:podocalyxin; C097007:podocalyxin-like protein 1, Oryctolagus cuniculus