title: Expression and chromosome location of hamster Ku70 and Ku80.
abstract: Ku proteins play an important role in DNA double-strand break (DSB) repair, chromosome maintenance, and growth regulation. To understand the fundamental characteristics of Ku proteins, we examined the electrophoretic mobility and expression of hamster Ku70 and Ku80 and determined the chromosome locations of their genes. The electrophoretic mobility of hamster Ku proteins are different from that of human Ku proteins. No significant changes in the quantity of Ku proteins were observed in CHO-K1 cells treated with 10 Gy of ionizing radiation, suggesting that both proteins are expressed constitutively in amounts adequate to repair DNA DSBs. The chromosome locations of the Ku genes were determined by direct R-banding fluorescence in situ hybridization. The Ku70 gene was localized to Syrian hamster chromosome 4qa4.1--> qa4.2 and Chinese hamster chromosome 2p3.1, and the Ku80 gene was localized to Syrian hamster chromosome 4qb5--> qb6.1 and Chinese hamster chromosome 2p3.5-->p3.6. These results provide clues to the biological functions of Ku, as well as useful information for constructing comparative chromosome maps between hamsters and other mammalian species, including human, mouse, and rat.
authors.affiliation: Genome Research Group, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan. mkoike@nirs.go.jp
authors.forename: M
authors.initials: M
authors.lastname: Koike
authors.forename: A
authors.initials: A
authors.lastname: Kuroiwa
authors.forename: A
authors.initials: A
authors.lastname: Koike
authors.forename: T
authors.initials: T
authors.lastname: Shiomi
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
mesh_terms: D000818:Animals; D034961:Antigens, Nuclear; D015153:Blotting, Western; D016466:CHO Cells; D002871:Chromosome Banding; D002875:Chromosomes / Q000235:genetics; D006224:Cricetinae; D003412:Cricetulus / Q000235:genetics*; D004265:DNA Helicases; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004307:Dose-Response Relationship, Radiation; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D000072200:Ku Autoantigen; D008647:Mesocricetus / Q000235:genetics*; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D020161:Physical Chromosome Mapping; D014965:X-Rays
chemical_list: D034961:Antigens, Nuclear; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D004265:DNA Helicases; C106893:XRCC5 protein, human; C000606509:Xrcc6 protein, human; C000606510:Xrcc6 protein, mouse; C000606511:Xrcc6 protein, rat; D000072200:Ku Autoantigen