title: Purification, characterization and differentiation-dependent expression of a perchloric acid soluble protein from rat kidney.
abstract: We have recently reported the presence of a novel perchloric acid soluble protein in rat liver (PSP1) that inhibits cell-free protein synthesis in a rabbit reticulocyte system. While studying the perchloric acid soluble proteins from different tissues of rats, we found that the kidney protein cross-reacted with antibody against the PSP1. In this investigation, we have purified a perchloric acid soluble protein from the rat kidney and studied its characterization and expression. The protein extracted from the postmitochondrial supernatant fraction with 5% perchloric acid was purified by ammonium sulfate fractionation and CM-Sephadex chromatography. By immunoscreening with the rabbit antisera against the PSP1, we detected a cDNA that contained an open reading frame of 411 bp, encoding a 137 amino-acid protein with a molecular mass of 14,149 daltons. The deduced amino acid sequence was completely identical with that of PSP1 from rat liver. The perchloric acid soluble protein from rat kidney (K-PSP1) also inhibited cell-free protein synthesis in the rabbit reticulocyte lysate system in a different manner than RNase A. Immunohistochemistry showed that the expression of K-PSP1 increased from fetal 17th day to postnatal 4th week, and it remained almost the same until the 7th week of postnatal age. Furthermore, the expression of K-PSP1 in the kidney of the nephrotic rat model was shown to be differentiation dependent. On the other hand, the expression of K-PSP1 in renal tumor cells was downregulated as compared with intact tissue. These results suggest that the expression of K-PSP1 is regulated in a differentiation-dependent manner in the kidney.
authors.affiliation: Department of Nutrition, University of Tokushima School of Medicine, Kuramoto, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Asagi
authors.forename: T
authors.initials: T
authors.lastname: Oka
authors.forename: K
authors.initials: K
authors.lastname: Arao
authors.forename: I
authors.initials: I
authors.lastname: Suzuki
authors.forename: M K
authors.initials: MK
authors.lastname: Thakur
authors.forename: K
authors.initials: K
authors.lastname: Izumi
authors.forename: Y
authors.initials: Y
authors.lastname: Natori
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D003001:Cloning, Molecular; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics; D006360:Heat-Shock Proteins / Q000737:chemistry*; D007150:Immunohistochemistry; D007668:Kidney / Q000737:chemistry*; D007680:Kidney Neoplasms / Q000503:physiopathology; D008297:Male; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis; D010472:Perchlorates / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000737:chemistry; D011506:Proteins / Q000737:chemistry*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012260:Ribonucleases; D017422:Sequence Analysis, DNA; D012995:Solubility
chemical_list: D006360:Heat-Shock Proteins; D009363:Neoplasm Proteins; D010472:Perchlorates; D011500:Protein Synthesis Inhibitors; D011506:Proteins; D012333:RNA, Messenger; C097211:Rida protein, rat; D012260:Ribonucleases