title: Identification of a truncated ratp28-related protein expressed in kidney.
abstract: An RT-PCR based strategy to clone the membrane-associated steroid binding protein ratp28 additionally amplified a novel sequence-related PCR product termed HC5. The HC5 PCR product was cloned and sequenced and showed 94% nucleotide sequence similarity to ratp28. The HC5 cDNA sequence open reading frame encodes a predicted 75 amino acid (8.0kDa) protein, and is therefore truncated compared to ratp28 (195 amino acids, 21.6kDa). In vitro transcription and translation of the HC5 cDNA resulted in the production of 2 proteins of approximately 8 and 6kDa. Restriction digests from various tissues demonstrated that liver and heart expressed primarily ratp28 mRNA whereas kidney and blood contained both ratp28 and HC5 transcripts. Phage display was employed to generate an antibody fragment to a peptide sequence conserved in ratp28 and HC5. Western blotting identified a 10kDa protein in cytosolic fractions of rat kidney. The function of HC5 remains to be determined.
authors.affiliation: Department of Molecular and Cell Biology, Institute of Medical Sciences, University of Aberdeen, Aberdeen, UK.
authors.forename: Val
authors.initials: V
authors.lastname: Leel
authors.forename: Lucy J
authors.initials: LJ
authors.lastname: Elrick
authors.forename: Jorges
authors.initials: J
authors.lastname: Solares
authors.forename: Nicola
authors.initials: N
authors.lastname: Ingram
authors.forename: Keith A
authors.initials: KA
authors.lastname: Charlton
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Porter
authors.forename: Matthew C
authors.initials: MC
authors.lastname: Wright
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D002352:Carrier Proteins / Q000096:biosynthesis / Q000737:chemistry*; D003001:Cloning, Molecular; D017124:Conserved Sequence; D003600:Cytosol / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D047908:Intracellular Signaling Peptides and Proteins; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D008861:Microsomes / Q000378:metabolism; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D019151:Peptide Library; D010455:Peptides / Q000737:chemistry; D010477:Perfusion; D010957:Plasmids / Q000378:metabolism; D011376:Progesterone-Binding Globulin / Q000737:chemistry*; D011485:Protein Binding; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution; D014158:Transcription, Genetic
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; C484955:HC5 protein, rat; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D019151:Peptide Library; D010455:Peptides; D011376:Progesterone-Binding Globulin; D012333:RNA, Messenger; C484954:Ratp28 protein, rat