tailieunhanh - Báo cáo khoa học: Brox, a novel farnesylated Bro1 domain-containing protein that associates with charged multivesicular body protein 4 (CHMP4)

Human Brox is a newly identified 46 kDa protein that has a Bro1 domain-like sequence and a C-terminal thioester-linkage site of isoprenoid lipid (CAAX motif) (C standing for cysteine, A for generally aliphatic amino acid, and X for any amino acid). | ễFEBS Journal Brox a novel farnesylated Bro1 domain-containing protein that associates with charged multivesicular body protein 4 CHMP4 Fumitaka Ichioka Ryota Kobayashi Keiichi Katoh Hideki Shibata and Masatoshi Maki Department of Applied Molecular Biosciences Graduate Schoolof BioagriculturalSciences Nagoya University Japan Keywords Alix Bro1 CHMP4 ESCRT-III farnesylation Correspondence M. Maki Department of Applied Molecular Biosciences Graduate School of BioagriculturalSciences Nagoya University Furo-cho Chikusa-ku Nagoya 464-8601 Japan Fax 81 52 789 5542 Tel 81 52 789 4088 E-mail mmaki@ Database The nucleotide sequence of the human Brox cDNA is available in the DDBJ EMBL Gen-Bank database under accession number AB276123 Received 11 October 2007 revised 5 December 2007 accepted 10 December 2007 doi Human Brox is a newly identified 46 kDa protein that has a Brol domainlike sequence and a C-terminal thioester-linkage site of isoprenoid lipid CAAX motif C standing for cysteine A for generally aliphatic amino acid and X for any amino acid . Mammalian Alix and its yeast ortholog Brol are known to associate with charged multivesicular body protein 4 CHMP4 a component of endosomal sorting complex required for transport III via their Brol domains and to play roles in sorting of ubiquitinat-ed cargoes. We investigated whether Brox has an authentic Brol domain on the basis of its capacity for interacting with CHMP4s. Both Strep Tactin binding sequence Strep -tagged wild-type Brox Strep-BroxWT and Strep-tagged farnesylation-defective mutant Cys fi Ser mutation Strep-BroxC408S pulled down FLAG-tagged CHMP4b that was coexpressed in HEK293 cells. Treatment of cells with a farnesyltransferase inhibitor FTI-277 caused an electrophoretic mobility shift of Strep-BroxWT and the mobility coincided with that of Strep-BroxC408S. The inhibitor also caused a mobility shift of endogenous Brox detected by western blotting using .