A 54-kDa protein related to ras-guanine nucleotide release factor expressed in the rat exocrine pancreas
A 54-kDa protein related to ras-guanine nucleotide release factor expressed in the rat exocrine pancreas
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与大鼠外分泌胰腺中表达的 ras-鸟嘌呤核苷酸释放因子相关的 54 kDa 蛋白
DOI：
10.1007/s004410050896
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发表时间：
1997
影响因子：
3.6
通讯作者：
M. Moran
中科院分区：
文献类型：
--
作者：
P. S. Tung;N. P. Fam;Luping Chen;M. Moran
摘要：采用聚合酶链反应从小鼠胚胎干细胞mRNA中扩增编码ras-鸟嘌呤核苷酸释放因子（ras-GRF 1）催化区的cDNA。制备针对该蛋白质的抗体并进行亲和纯化。大鼠组织裂解物的Western免疫印迹显示，如预期的那样，在脑中有一个140 kDa的蛋白质，但除此之外，在胰腺中还发现了一个强免疫反应性的54 kDa蛋白质p54。通过逆转录酶偶联聚合酶链反应分析，在RNA水平上证实了胰腺中ras-GRF 1的表达;因此，p54可能对应于ras-GRF 1的一种形式或一种密切相关的蛋白质。用酶联免疫细胞化学和免疫金电镜观察p54的细胞和亚细胞定位。在胰腺中，p54主要在腺泡细胞中表达，其定位于沿着基底侧和顶侧质膜。培养的腺泡的间接免疫荧光显微镜进一步表明，质膜定位的p54依赖于维护腺泡组织型和有组织的腺泡结构。当原代腺泡细胞被允许消散成单层培养缺乏酶原颗粒，ras-GRF 1染色成为胞质。我们的研究结果表明，ras-GRF 1参与胰腺的结构和功能。
Abstract.The polymerase chain reaction was used to amplify a cDNA encoding the catalytic region of ras-guanine nucleotide release factor (ras-GRF1) from mouse embryonic stem cell mRNA. Antibodies directed against this protein were prepared and affinity purified. Western immunoblotting of rat tissue lysates revealed a 140-kDa protein in brain as expected but, in addition, a strongly immunoreactive 54-kDa protein, p54, was identified in pancreas. Expression of ras-GRF1 in pancreas was confirmed at the RNA level by reverse-transcriptase-coupled polymerase chain reaction analysis; p54 may therefore correspond to a form of ras-GRF1 or a closely related protein. The cellular and subcellular localization of p54 was investigated by enzyme-linked immunocytochemistry and immunogold electron microscopy. In the pancreas, p54 was expressed primarily in acinar cells, where it was localized along the basolateral and apicolateral plasma membranes. Indirect immunofluorescence microscopy of cultured acini further indicated that the plasma membrane localization of p54 was dependent on the maintenance of the acinar histotype and organized acinar structure. When primary acinar cells were permitted to dissipate into monolayer cultures devoid of zymogen granules, ras-GRF1 staining became cytosolic. Our results suggest that ras-GRF1 is involved in the structure and function of the pancreas.
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影响因子：
11.2
作者：
Joyce Bos
通讯作者：
Joyce Bos
影响因子：
56.9
作者：
GILOH, H;SEDAT, JW
通讯作者：
SEDAT, JW
成纤维细胞生长因子对体外大鼠胰腺腺泡细胞的直接营养作用。
影响因子：
3.1
作者：
Hoshi,H;Logsdon,CD
通讯作者：
Logsdon,CD
影响因子：
56.9
作者：
CHARDIN, P;CAMONIS, JH;BARSAGI, D
通讯作者：
BARSAGI, D
影响因子：
56.9
作者：
BONFINI, L;KARLOVICH, CA;BANERJEE, U
通讯作者：
BANERJEE, U