The PLAC1 protein localizes to membranous compartments in the apical region of the syncytiotrophoblast
The PLAC1 protein localizes to membranous compartments in the apical region of the syncytiotrophoblast
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DOI：
10.1002/mrd.20673
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发表时间：
2007-07-01
影响因子：
2.5
通讯作者：
Bick, Roger
中科院分区：
文献类型：
--
作者：
Fant, Michael;Barerra-Saldana, Hugo;Bick, Roger
PLAC1是滋养层细胞特异性基因，定位于X染色体上对胎盘发育重要的位点。我们以前已经表明，PLAC1基因表达与滋养层分化。本研究的目的是确定PLAC1多肽的定位，作为了解其功能的先决条件。产生对推定的PLACl多肽特异的多克隆抗体。胎盘PLAC1在滋养层细胞的亚细胞定位，通过免疫组化分析的人胎盘的亚细胞组分的免疫印迹分析。胎盘组织的免疫组织化学分析表明，PLAC1蛋白定位于细胞顶端区域的分化合胞体滋养层。解卷积免疫荧光显微镜证实定位于合体滋养层的顶端区域。其分布包括细胞内区室以及与面向母体的微绒毛刷状缘膜（MM）密切相关的位点。这些发现得到了亚细胞组分免疫印迹分析的支持。一个30 kDa的带与胎盘裂解物的微粒体部分，但不是线粒体，核，或可溶性部分，表明PLAC1的目标是膜的位置。从合体滋养层膜的面向胎儿的基底面（BM）和面向母体的MVM获得质膜。PLAC1免疫反应性仅在来自顶MVM的膜组分中检测到，与免疫组织化学分析一致。这些数据表明，PLAC1蛋白主要局限于分化的滋养层，定位于合体滋养层顶端区域的细胞内膜室，并与其顶端微绒毛膜表面相关。
PLAC1 is a trophoblast-specific gene that maps to a locus on the X-chromosome important to placental development. We have previously shown that PLAC1 gene expression is linked to trophoblast differentiation. The objective of this study was to define the localization of the PLAC1 polypeptide as a prerequisite to understanding its function. Polyclonal antibodies specific for the putative PLAC1 polypeptide were generated. The subcellular localization of PLAC1 in the trophoblast was examined by immunohistochemical analysis of human placenta complemented by immunoblot analysis of subcellular fractions. Brightfield immunohistochemical analysis of placental tissue indicated that the PLAC1 protein localizes to the differentiated syncytiotrophoblast in the apical region of the cell. Deconvlution immunofluorescence microscopy confirmed localization to the apical region of the syncytiotrophoblast. Its distribution included both intracellular compartments as well as loci in close association with the maternal-facing, microvillous brush border membrane (MM. These findings were supported by immunoblot analysis of subcellular fractions. A 30 kDa band was associated with the microsomal fraction of placental lysates but not the mitochondrial, nuclear, or soluble fractions, suggesting PLAC1 is targeted to a membrane location. Plasma membranes were obtained from the fetal-facing, basal surface (BM) and the maternal-facing, MVM of the syncytiotrophoblast membrane. PLAC1 immunoreactivity was only detected in membrane fractions derived from the apical MVM consistent with immunohistochemical analyses. These data demonstrate that the PLAC1 protein is restricted primarily to the differentiated trophoblast, localizing to intracellular membranous compartment(s) in the apical region of the syncytiotrophoblast and associated with its apical, microvillous membrane surface.