X Mo1, N X Nguyen, P A McEwan, X Zheng, J A López, J Emsley, R Li. 1. Center for Membrane Biology, Department of Biochemistry and Molecular Biology, The University of Texas Health Science Center at Houston, Houston, TX 77030, USA.
Abstract
BACKGROUND: The mechanism of assembly of the platelet glycoprotein (GP) Ib-IX complex from GPIbalpha, GPIbbeta and GPIX subunits is not entirely clear. In this complex, ectodomains of both GPIbbeta and GPIX subunits contain two leucine-rich repeats (LRR) and share high sequence similarity. However, they differ noticeably in stability, hampering further analysis of their interaction. OBJECTIVES AND METHODS: Guided by analysis of the LRR structure, we report a well-folded Ibbeta/IX chimera and its usage in dissecting GPIX function. RESULTS: In this chimera, three non-contiguous sequences that may constitute the putative convex surface of the GPIbbeta ectodomain are replaced by their GPIX counterparts. Like GPIbbeta but unlike GPIX ectodomain, it can secrete from transfected Chinese hamster ovary cells and fold into a stable conformation. Furthermore, replacing the ectodomain in GPIX with the Ibbeta/IX chimera, but not the GPIbbeta ectodomain, preserved its interaction with GPIbbeta as demonstrated by its native-like GPIbbeta-induced increase in surface expression and coimmunoprecipitation. CONCLUSIONS: The putative convex surface of the LRR domain in GPIX is sufficient, in the context of full-length subunit, to mediate its association with GPIbbeta.
BACKGROUND: The mechanism of assembly of the platelet glycoprotein (GP) Ib-IX complex from GPIbalpha, GPIbbeta and GPIX subunits is not entirely clear. In this complex, ectodomains of both GPIbbeta and GPIX subunits contain two leucine-rich repeats (LRR) and share high sequence similarity. However, they differ noticeably in stability, hampering further analysis of their interaction. OBJECTIVES AND METHODS: Guided by analysis of the LRR structure, we report a well-folded Ibbeta/IX chimera and its usage in dissecting GPIX function. RESULTS: In this chimera, three non-contiguous sequences that may constitute the putative convex surface of the GPIbbeta ectodomain are replaced by their GPIX counterparts. Like GPIbbeta but unlike GPIX ectodomain, it can secrete from transfected Chinese hamster ovary cells and fold into a stable conformation. Furthermore, replacing the ectodomain in GPIX with the Ibbeta/IX chimera, but not the GPIbbeta ectodomain, preserved its interaction with GPIbbeta as demonstrated by its native-like GPIbbeta-induced increase in surface expression and coimmunoprecipitation. CONCLUSIONS: The putative convex surface of the LRR domain in GPIX is sufficient, in the context of full-length subunit, to mediate its association with GPIbbeta.
Authors: William A Barton; Betty P Liu; Dorothea Tzvetkova; Philip D Jeffrey; Alyson E Fournier; Dinah Sah; Richard Cate; Stephen M Strittmatter; Dimitar B Nikolov Journal: EMBO J Date: 2003-07-01 Impact factor: 11.598
Authors: Eric G Huizinga; Shizuko Tsuji; Roland A P Romijn; Marion E Schiphorst; Philip G de Groot; Jan J Sixma; Piet Gros Journal: Science Date: 2002-08-16 Impact factor: 47.728
Authors: Jingrong Tang; Sara Stern-Nezer; Po-Ching Liu; Ludmila Matyakhina; Michael Riordan; Naomi L C Luban; Peter J Steinbach; Stephen G Kaler Journal: Thromb Haemost Date: 2004-07 Impact factor: 5.249
Authors: X Liang; S R Russell; S Estelle; L H Jones; S Cho; M L Kahn; M C Berndt; S T Bunting; J Ware; R Li Journal: J Thromb Haemost Date: 2013-12 Impact factor: 5.824
Authors: Rong Yan; Xi Mo; Angel M Paredes; Kesheng Dai; Francois Lanza; Miguel A Cruz; Renhao Li Journal: Biochemistry Date: 2011-11-18 Impact factor: 3.162
Authors: Hao Zhou; Yali Ran; Qi Da; Tanner S Shaw; Dan Shang; Anilkumar K Reddy; José A López; Christie M Ballantyne; Jerry Ware; Huaizhu Wu; Yuandong Peng Journal: J Immunol Date: 2016-05-20 Impact factor: 5.422
Authors: Paul A McEwan; Wenjun Yang; Katherine H Carr; Xi Mo; Xiaofeng Zheng; Renhao Li; Jonas Emsley Journal: Blood Date: 2011-09-08 Impact factor: 22.113