title: Molecular cloning, expression characterization, and mapping of a novel putative inhibitor of rho GTPase activity, RTKN, to D2S145-D2S286.
abstract: The Rho proteins are a class of small molecular GTPases that regulate multiple fundamental cellular processes by mediating the G-protein-coupled receptor signaling pathway. Rhotekin, which is one of the downstream target molecules of Rho with a Rho binding motif class I domain, can inhibit endogenous or RhoGAP-stimulating Rho GTPase activity to regulate the signaling pathway. Here, a novel human cDNA containing an intact open reading frame that encodes 544 amino acids has been identified. As this putative protein shares 84. 6% amino acid identity with mouse Rhotekin, and has a tandem Rho binding domain class 1 and Pleckstrin homology domain, it was regarded as a human homologue of the mouse Rhotekin and assigned a symbol of RTKN. With the human Rhotekin cDNA as a probe, Northern hybridization revealed that a 4.0-kb transcript was expressed at a high level in prostate and at a middle level in 13 of 16 tissues examined, but it cannot be detected in liver and lung tissues. Meanwhile, a 2.4-kb transcript was expressed at a middle level in prostate and another 3.0-kb transcript in kidney. In addition, the RTKN gene was localized to chromosome 2p13 between markers D2S145 at 6.94 cR (LOD > 12) and D2S286 at 8.12 cR (LOD > 9.7) by radiation hybrid panel mapping. Compared with BAC clone AC005041 sequence, there were 12 exons for the RTKN gene and it spanned a 16.5-kb genomic region.
authors.affiliation: State Key Laboratory of Genetic Engineering, Fudan University, Shanghai, 200433, People's Republic of China. longyu@fudan.edu.cn
authors.forename: Q
authors.initials: Q
authors.lastname: Fu
authors.forename: L
authors.initials: L
authors.lastname: Yu
authors.forename: Q
authors.initials: Q
authors.lastname: Liu
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.forename: H
authors.initials: H
authors.lastname: Zhang
authors.forename: S
authors.initials: S
authors.lastname: Zhao
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D051017:Apoptosis Regulatory Proteins; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics*; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics; D003001:Cloning, Molecular; D019204:GTP-Binding Proteins; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D008969:Molecular Sequence Data; D009928:Organ Specificity; D011467:Prostate / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics; D012333:RNA, Messenger / Q000096:biosynthesis; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D020741:rho GTP-Binding Proteins / Q000037:antagonists & inhibitors*
chemical_list: D051017:Apoptosis Regulatory Proteins; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D012333:RNA, Messenger; C100494:RTKN protein, human; C498395:Rtkn protein, mouse; D019204:GTP-Binding Proteins; D020741:rho GTP-Binding Proteins