TIMAP-protein phosphatase 1-complex controls endothelin-1 production via ECE-1 dephosphorylation

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• 作者：Anita Boratkó ; ^a ; Zoltá ; n Veré ; b^b ; Goran Petrovski^b ; Csilla Csortos^a ; ^{csortos@med.unideb.hu" class="auth_mail" title="E-mail the corresponding author}
• 关键词：BPAEC ; bovine pulmonary artery endothelial cell ; EC ; endothelial cell ; ECIS ; electric cell-substrate impedance sensing ; ET-1 ; endothelin-1 ; ECE-1 ; endotheiln converting enzyme-1 ; ERM ; ezrin-radixin-moesin ; HPAEC ; human pulmonary artery endothelial cells ; MYPT ; myosin phosphatase targeting subunit ; PKA ; protein kinase A ; PKC ; protein kinase C ; PMA ; phorbol 12-myristate 13-acetate ; PP1 ; protein phosphatase 1 ; PP1c ; catalytic subunit of protein phosphatase 1 ; TIMAP ; TGF-β inhibited membrane associa
• 刊名：International Journal of Biochemistry and Cell Biology
• 出版年：2016
• 出版时间：April 2016
• 年：2016
• 卷：73
• 期：Complete
• 页码：11-18
• 全文大小：2306 K

文摘

Endothelin induced signaling pathways can affect blood pressure and vascular tone, but the influence of endothelins on tumor cells is also significant. We have detected elevated endothelin-1 secretion from TIMAP (TGF-β inhibited membrane associated protein) depleted vascular endothelial cells. The autocrine signaling activated by the elevated endothelin-1 level through the ET_B receptors evoked an angiogenic-like phenotype, the cells assumed an elongated morphology, and enhanced tube formation and wound healing abilities. The depleted protein, TIMAP, is a highly specific and abundant protein in the endothelial cells, and it is a regulatory/targeting subunit for the catalytic subunit of protein phosphatase 1 (PP1c). Protein-protein interaction between the TIMAP-PP1c complex and the endothelin converting enzyme-1 (ECE-1) was detected, the latter of which is a transmembrane protein that produces the biologically active 21-amino acid form of endothelin-1 from proendothelin. The results indicate that silencing of TIMAP induces a reduction in TIMAP-PP1c activity connected to ECE-1. This leads to an increase in the amount of ECE-1 protein in the plasma membrane and a consequent increase in endothelin-1 secretion. Similarly, activation of PKC, the kinase responsible for ECE-1 phosphorylation increased ECE-1 protein level in the membrane fraction of the endothelial cells. The elevated ECE-1 level was mitigated in time in normal cells, but was clearly preserved in TIMAP-depleted cells. Overall, our results indicate that PKC-phosphorylated ECE-1 is a TIMAP-PP1c substrate and this phosphatase complex has an important role in endothelin-1 production of EC through the regulation of ECE-1 activity.