Vps33b regulates Vwf-positive vesicular trafficking in megakaryocytes
Vps33b regulates Vwf-positive vesicular trafficking in megakaryocytes
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Vps33b 调节巨核细胞中 Vwf 阳性囊泡运输
DOI：
10.1002/path.4762
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发表时间：
2016-09-01
影响因子：
7.3
通讯作者：
Liu, Junling
中科院分区：
文献类型：
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作者：
Dai, Jing;Lu, Yeling;Liu, Junling
空泡蛋白分选相关蛋白33 b（VPS 33 B）的突变导致关节弯曲、肾功能不全和胆汁淤积综合征，以及受影响患者血小板颗粒的缺乏。开发条件性Vps 33 b敲除小鼠以研究Vps 33 b在血小板颗粒形成中的功能。我们发现，早期胚胎Vps 33 b的缺失是致命的。PF 4-Cre驱动的巨核细胞靶向Vps 33 b基因缺失大大降低了血小板中Vps 33 b的表达，但对血小板颗粒形成和蛋白含量没有影响。他莫昔芬诱导的造血干细胞（HSC）特异性Vps 33 b缺失完全耗尽血小板中的Vps 33 b，导致缺乏颗粒，并增加血小板和巨核细胞中的空泡数量。VPS 33 B与VIPAS 39、微管蛋白和SEC 22 B的结合通过在人胚肾293 T（HEK 293 T）细胞中的免疫共沉淀、质谱和免疫印迹来鉴定。此外，下拉实验显示，VIPAS 39绑定到完整的VPS 33 B，相反，微管蛋白和SEC 22 B分别与VPS 33 B的sec 1样结构域相互作用。巨核细胞中Vps 33 b缺陷干扰Vipas 39和Sec 22 b向前血小板的再分布，并中断Sec 22 b与Vwf阳性囊泡的共定位。在这项研究中提出的数据表明，Vps 33 b可能是通过促进VWF阳性囊泡贩运到巨核细胞中的颗粒相关空泡参与颗粒形成。版权所有（c）2016大不列颠和爱尔兰病理学会。由John Wiley & Sons有限公司出版
Mutations of vacuolar protein sorting-associated protein 33b (VPS33B) cause arthrogryposis, renal dysfunction, and cholestasis syndrome, and a lack of platelet -granules in the affected patients. Conditional Vps33b knockout mice were developed to investigate the function(s) of Vps33b in platelet -granule formation. We found that early embryonic deletion of Vps33b was lethal. PF4-Cre-driven megakaryocyte-targeted Vps33b gene deletion greatly diminished Vps33b expression in platelets, but had no effect on platelet -granule formation and protein content. Tamoxifen-induced, haematopoietic stem cell (HSC)-specific Vps33b deletion completely depleted Vps33b in platelets, caused the absence of -granules, and increased the number of vacuoles in platelets and megakaryocytes. VPS33B association with VIPAS39, -tubulin, and SEC22B was identified by co-immunoprecipitation, mass spectra, and immunoblotting in human embryonic kidney 293T (HEK293T) cells. Also, pull-down experiments revealed that VIPAS39 bound to intact VPS33B; in contrast, -tubulin and SEC22B separately interacted with the sec1-like domains of VPS33B. Vps33b deficiency in megakaryocytes disturbs the redistribution of Vipas39 and Sec22b to proplatelets, and interrupted the co-localization of Sec22b with Vwf-positive vesicles. The data presented in this study suggest that Vps33b is involved in -granule formation possibly by facilitating the Vwf-positive vesicular trafficking to -granule-related vacuoles in megakaryocytes. Copyright (c) 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.