Regulated Secretion in Platelets: Identification of Elements of the Platelet Exocytosis Machinery

Author:

Lemons Paula P.1,Chen Dong1,Bernstein Audrey M.1,Bennett Mark K.1,Whiteheart S.W.1

Affiliation:

1. From the Department of Biochemistry, University of Kentucky College of Medicine, Lexington, KY; and the Department of Molecular and Cellular Biology, University of California, Berkeley CA.

Abstract

To further characterize the molecular mechanisms of platelet function, we have sought to identify some of the proteins that mediate the secretory events of the platelet release reaction. We report that platelets contain the general elements of the membrane transport apparatus: N-ethylmaleimide sensitive fusion protein (NSF ), p115/transcytosis-associated protein (p115/TAP), and the soluble NSF attachment proteins (α- and, γ-SNAP). The cDNAs encoding two of these proteins, α- and γ-SNAP, have been cloned from a human platelet-derived cDNA library. Platelet membrane extracts possess SNAPreceptor (SNARE) activity, suggesting that the class of proteins (SNAREs) proposed to provide the specificity for vesicle docking and membrane fusion are present in platelets. To identify these proteins, we have used specific antibodies against known SNAREs to probe platelet extracts. Syntaxin 2 and 4 can be readily detected in platelet membrane preparations and are shown to participate in 20 S complex formation. Syntaxin 1, 3, and 5 could not be detected. Other known SNARE and SNARE-associated proteins such as vesicle-associated membrane protein (VAMP)/synaptobrevin 2, SNAP-25, synaptophysin, or synaptotagmin I could not be immunochemically detected in platelet membrane preparations. The presence of both the general transport proteins (NSF and SNAPs) and specific transport proteins (syntaxin 2 and 4) indicates that platelet exocytosis uses a molecular mechanism similar to other secretory cells such as neurons. However, the subcellular concentrations of these proteins suggest that, unlike neuronal secretion, granule-to plasma membrane docking may be the limiting step in platelet exocytosis.

Publisher

American Society of Hematology

Subject

Cell Biology,Hematology,Immunology,Biochemistry

Reference60 articles.

1. Molecular mechanisms of platelet activation.;Siess;Physiol Rev,1989

2. Redistribution of alpha-granules and their contents in thrombin-stimulated platelets.;Stenberg;J Cell Biol,1984

3. The platelet open canicular system: A final common pathway.;Escolar;Blood Cells,1991

Cited by 103 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3