title: Cloning of porcine platelet glycoprotein Ibα and comparison with the human homolog.
abstract: Glycoprotein Ib-IX-V (GPIb-IX-V) is a platelet adhesion receptor complex that initiates platelet aggregation. Glycoprotein Ibα (GPIbα) is the central component of the GPIb-IX-V complex, anchoring the complex to the cytoskeleton and harboring  the binding site for von Willebrand factor (vWF). Previous studies suggest that the coagulation function in pigs differs from that in humans, especially with respect to the interaction between vWF and platelets. However, we have little knowledge about the function of porcine platelets, which  is important with regard to studies of cardiovascular disease, clotting, and surgery that use pigs as animal models. To extend this information, we cloned and analyzed the porcine GPIbα sequence. Porcine GPIbα contains 1891 nucleotides and includes an open reading frame that encodes  627 amino acids. The nucleotide sequence showed 67% identity with human GPIbα, whereas the deduced amino acid sequences were 59% identical. The vWF binding domain shares the highest identity among different species, whereas the PEST domain shows variations. Evaluation of platelet function  by using ristocetin-induced platelet aggregation revealed remarkably lower levels of aggregation in porcine than human platelets. According to the sequence analysis and platelet aggregation tests, we propose that the function of GPIbα, especially regarding the ristocetin-vWF-GPIbα  interaction, differs between pigs and humans. This characterization of porcine GPIbα will enhance our knowledge of the porcine coagulation system.
authors.affiliation: Key Laboratory of Transplant Engineering and Immunology, Ministry of Health, Regenerative Medicine Research Center, West China Hospital, Sichuan University, Chengdu, China.
authors.forename: Meimei
authors.initials: M
authors.lastname: Shi
authors.forename: Jianlin
authors.initials: J
authors.lastname: Qiao
authors.forename: Yang
authors.initials: Y
authors.lastname: Shen
authors.forename: Yanrong
authors.initials: Y
authors.lastname: Lu
authors.forename: Younan
authors.initials: Y
authors.lastname: Chen
authors.forename: Jingqiu
authors.initials: J
authors.lastname: Cheng
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D006801:Humans; D008969:Molecular Sequence Data; D010974:Platelet Aggregation / Q000502:physiology; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity; D013552:Swine; D013556:Swine, Miniature / Q000235:genetics*
chemical_list: D019038:Platelet Glycoprotein GPIb-IX Complex