title: Grtp1, a novel gene regulated by growth hormone.
abstract: An in vitro model of GH-responsive cells was subjected to microarray analysis to identify a novel gene regulated by GH. This 258 amino acid protein, we term GH Regulated TBC Protein-1 (GRTP1), contains the TBC signature motif of GTPase activator proteins of Rab-like small GTPases. Northern blot analysis revealed a 1.3 kb major mRNA species, most abundant in testes. TaqMan assay confirmed that in the mouse, Grtp1 is expressed at highest levels in testes, with lesser abundance in intestine, kidney, lung, and liver. In the testis, expression of Grtp1 significantly increases post-pubertally. Administration of GH to mice increased levels of GRTP1 mRNA in testes (140%), but decreased GRTP1 mRNA abundance in kidney (50%) and liver (25%). Grtp1 was localized to mouse proximal chromosome 8. Orthologs of this protein are present in human, mouse, rat, and drosophila suggesting that GRTP1 has an important biological role(s).
authors.affiliation: Department of Pediatrics, Children's Hospital of Pittsburgh, Pennsylvania 15213, USA.
authors.forename: C
authors.initials: C
authors.lastname: Lu
authors.forename: J
authors.initials: J
authors.lastname: Kasik
authors.forename: D A
authors.initials: DA
authors.lastname: Stephan
authors.forename: S
authors.initials: S
authors.lastname: Yang
authors.forename: M A
authors.initials: MA
authors.lastname: Sperling
authors.forename: R K
authors.initials: RK
authors.lastname: Menon
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects*; D013006:Growth Hormone / Q000494:pharmacology*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009928:Organ Specificity; D051381:Rats; D020691:rab GTP-Binding Proteins / Q000187:drug effects / Q000235:genetics
chemical_list: C437906:GH Regulated TBC Protein-1; D013006:Growth Hormone; D020691:rab GTP-Binding Proteins