tailieunhanh - Báo cáo khoa học: Crystal structure of importin-a bound to a peptide bearing the nuclear localisation signal from chloride intracellular channel protein 4

It has been reported that a human chloride intracellular channel (CLIC) protein, CLIC4, translocates to the nucleus in response to cellular stress, facilitated by a putative CLIC4 nuclear localization signal (NLS). The CLIC4 NLS adopts ana-helical structure in the native CLIC4 fold. | 1FEBS Journal Crystal structure of importin-a bound to a peptide bearing the nuclear localisation signal from chloride intracellular channel protein 4 Andrew V. Mynott1 Stephen J. Harrop1 Louise J. Brown2 Samuel N. Breit3 Bostjan Kobe4 5 and Paul M. G. Curmi1 3 1 Schoolof Physics University of New South Wales Sydney NSW Australia 2 Department of Chemistry and Biomolecular Sciences Macquarie University Sydney NSW Australia 3 St Vincent s Centre for Applied MedicalResearch St Vincent s Hospitaland University of New South Wales Sydney NSW Australia 4 Schoolof Chemistry and Molecular Biosciences and Centre for Infectious Disease Research University of Queensland Brisbane Qld Australia 5 Institute for Molecular Bioscience University of Queensland Brisbane Qld Australia Keywords chloride intracellular channel protein CLIC4 importin-a nuclear localization signal NLS nucleocytoplasmic transport Correspondence P. Curmi Schoolof Physics University of New South Wales Sydney NSW 2052 Australia Fax 61 2 9385 6060 Tel 61 2 9385 4552 E-mail Received 17 November 2010 revised 31 January 2011 accepted 23 February 2011 doi It has been reported that a human chloride intracellular channel CLIC protein CLIC4 translocates to the nucleus in response to cellular stress facilitated by a putative CLIC4 nuclear localization signal NLS . The CLIC4 NLS adopts an a-helical structure in the native CLIC4 fold. It is proposed that CLIC4 is transported to the nucleus via the classical nuclear import pathway after binding the import receptor importin-a. In this study we have determined the X-ray crystal structure of a truncated form of importin-a lacking the importin-b binding domain bound to a CLIC4 NLS peptide. The NLS peptide binds to the major binding site in an extended conformation similar to that observed for the classical simian virus 40 large T-antigen NLS. A Tyr residue within the CLIC4 NLS makes surprisingly favourable interactions by .