PROHORMONE-CONVERTING ENZYMES - REGULATION AND EVALUATION OF FUNCTION USING ANTISENSE RNA
PROHORMONE-CONVERTING ENZYMES - REGULATION AND EVALUATION OF FUNCTION USING ANTISENSE RNA
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DOI：
10.1210/mend-5-12-2014
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发表时间：
1991-12-01
影响因子：
--
通讯作者：
MAINS, RE
中科院分区：
文献类型：
--
作者：
BLOOMQUIST, BT;EIPPER, BA;MAINS, RE
通过与酵母 Kex2 内切蛋白酶的同源性，已鉴定出几种假定的肽加工内切蛋白酶，包括弗林蛋白酶、PC2 和 PC1。 然而，哪些肽可能参与翻译后加工仍是一个悬而未决的问题。 为了能够将肽加工的生理变化与生化和分子生物学研究进行详细比较，我们克隆了 PC1 和 PC2 的大鼠垂体 cDNA。 大鼠、人类和小鼠 PC1、PC2 和弗林蛋白酶之间的氨基酸序列同源性一致，表明它们都是哺乳动物枯草杆菌蛋白酶样蛋白酶大家族的高度保守但独特的成员。 PC1 和 PC2 mRNA 在大鼠组织和培养细胞系中显示出有限的分布，这与组织特异性肽加工中的作用一致；弗林蛋白酶 mRNA 在这些组织和细胞系中的出现更为广泛，在许多非神经内分泌组织中含量很高。 在神经中间垂体中，PC1 和 PC2 mRNA 响应多巴胺能药物而受到显着调节，与 POMC、肽基甘氨酸 α-酰胺化单加氧酶和羧肽酶-H 的 mRNA 平行。 在 AtT-20 细胞中，PC1 mRNA 与 POMC 和肽基甘氨酸 α-酰胺化单加氧酶 mRNA 共同调节，以响应 CRH 和糖皮质激素。 当 AtT-20 细胞中内源性 PC1 mRNA 水平因 PC1 反义 RNA 的稳定表达而显着且特异性降低时，新合成的 POMC 衍生肽的生物合成标记显示出对正常 POMC 加工的实质性阻断。 这些数据与 PC1 蛋白在内切蛋白酶中的作用一致，无论是作为加工内切蛋白酶还是作为实际加工内切蛋白酶的激活剂。
Several putative peptide-processing endoproteases have been identified by homology to the yeast Kex2 endoprotease, including furin, PC2, and PC1. However, the question is still open as to which might be involved in peptide posttranslational processing. To enable detailed comparisons of physiological changes in peptide processing with biochemical and molecular biological studies, we cloned rat pituitary cDNAs for PC1 and PC2. The amino acid sequence homologies among rat, human, and mouse PC1, PC2, and furin are consistent with each being a highly conserved but distinct member of a larger family of mammalian subtilisin-like protease. PC1 and PC2 mRNAs show a restricted distribution among rat tissues and cultured cell lines, consistent with a role in tissue-specific peptide processing; the occurrence of furin mRNA among these tissues and cell lines is much more widespread, being high in many nonneuroendocrine tissues. In the neurointermediate pituitary, PC1 and PC2 mRNAs are strikingly regulated in response to dopaminergic agents, in parallel with mRNAs for POMC, peptidylglycine alpha-amidating monooxygenase, and carboxypeptidase-H. In AtT-20 cells, PC1 mRNA is coregulated with POMC and peptidylglycine alpha-amidating monooxygenase mRNAs in response to CRH and glucocorticoids. When the endogenous PC1 mRNA level in AtT-20 cells is significantly and specifically decreased by stable expression of antisense RNA to PC1, biosynthetic labeling of newly synthesized POMC-derived peptides shows a substantial blockade of normal POMC processing. These data are consistent with a role for PC1 protein in endoproteolysis, either as a processing endoprotease or as the activator of the actual processing endoprotease(s).