tailieunhanh - Báo cáo khoa học: Differential expression of eIF5A-1 and eIF5A-2 in human cancer cells

Eukaryotic translation initiation factor 5A (eIF5A) is the only cellular protein that contains the unusual amino acid hypusine [N e -(4-amino-2-hydroxybutyl)lysine]. Vertebrates carry two genes that encode two eIF5A isoforms, eIF5A-1 and eIF5A-2, which, in humans, are 84% identical. eIF5A-1 mRNA ( kb) and protein (18 kDa) are constitutively expressed in human cells. In contrast, expression of eIF5A-2 mRNA (– kb) and eIF5A-2 protein (20 kDa) varies widely. | iFEBS Journal Differential expression of eIF5A-1 and eIF5A-2 in human cancer cells Paul M. J. Clement1 Hans E. Johansson2 1 Edith C. Wolff1 and Myung H. Park1 1 Oraland PharyngealCancer Branch National institute of Dentaland CraniofacialResearch National institutes of Health Bethesda MD USA 2 CHORI Children s HospitalOakland Research Institute Oakland CA USA and Department of Celland Molecular Biology Uppsala University Sweden Keywords alternative polyadenylation eIF5A hypusine post-translationalmodification translation Correspondence M. H. Park Rm 211 Bldg 30 Oraland PharyngealCancer Branch National institute of Dental and Craniofacial Research National institutes of Health Bethesda MD 20892-4340 USA Fax 1 301 402 0823 Tel 1 301 496 5056 E-mail mhpark@ Present address Laboratory of ExperimentalOncology Catholic University of Leuven Herestraat 49 3000 Leuven Belgium IPresent address Biosearch Technologies Inc. 81 Digital Drive Novato CA 94949-5750 UsA Received 11 October 2005 revised 9 December 2005 accepted 16 January 2006 doi Eukaryotic translation initiation factor 5A eIF5A is the only cellular protein that contains the unusual amino acid hypusine Ne- 4-amino-2-hydroxybutyl lysine . Vertebrates carry two genes that encode two eIF5A isoforms eIF5A-1 and eIF5A-2 which in humans are 84 identical. eIF5A-1 mRNA kb and protein 18 kDa are constitutively expressed in human cells. In contrast expression of eIF5A-2 mRNA kb and eIF5A-2 protein 20 kDa varies widely. Whereas eIF5A-2 mRNA was demonstrable in most cells eIF5A-2 protein was detectable only in the colorectal and ovarian cancer-derived cell lines SW-480 and UACC-1598 which showed high overexpression of eIF5A-2 mRNA. Multiple forms of eIF5A-2 mRNA and kb were identified as the products of one gene with various lengths of 3 -UTR resulting from the use of different polyadenylation AAUAAA signals. The eIF5A-1 and eIF5A-2 precursor proteins were .