DSpace university logo mark
Advanced Search
Japanese | English 

NAOSITE : Nagasaki University's Academic Output SITE > School of Medicine > Bulletin > Acta Medica Nagasakiensia > Volume 48, No. 3-4 >

Review Article A Novel Regulatory Mechanism of Apoptosis by Calreticulin, a Molecular Chaperone in the Endoplasmic Reticulum

File Description SizeFormat
acta48_03_01_t.pdf1.11 MBAdobe PDFView/Open

Title: Review Article A Novel Regulatory Mechanism of Apoptosis by Calreticulin, a Molecular Chaperone in the Endoplasmic Reticulum
Authors: Ihara, Yoshito
Issue Date: 24-Dec-2003
Citation: Acta medica Nagasakiensia. 2003, 48(3-4), p.85-92
Abstract: Calreticulin (CRT) is a Ca"--binding lectin-like molecular chaperone of the lumen of the endoplasmic reticulum. Recently, CRT has been revealed to be a multi-functional molecule related with glycoprotein maturation and chaperone function, Ca" homeostasis, cell adhesion, cell signaling, transcriptional regulation, and nuclear transporting mechanisms. CRT is also essential for cardiac and neural development in mice, suggesting an importance in the regulation of cell survival and death during development. To examine the role of CRT in cardiac differentiation, we established CRT-overexpressiog myocardiac H9c2 cells, and investigated the effect of the overexpression on cardiac differentiation in vitro. We found that the cells transfected with the CRT gene were highly susceptible to apoptosis compared with controls. In the gene-transfected cells, Akt/ protein kinase B signaling was significantly suppressed during the differentiation. Furthermore, PP2A, a Ser/Thr protein phosphatase, was significantly upregulated implying a suppression of Akt signaling due to dephosphorylation of Alit by the upregulated PP2A via the regulation of Ca` homeostasis. Thus, overexpression of CRT promotes differentiation- dependent apoptosis in H9c2 cells by suppressing the Akt signaling pathway. Our findings demonstrate a novel mechanism in which cytoplasmic Akt signaling is modulated to cause apoptosis by a resident protein of the endoplasmic reticulum, CRT.
Keywords: calreticulin / endoplasmic reticulum / molecular chaperone / calcium / akt/protein kinase B / apoptosis
URI: http://hdl.handle.net/10069/16250
ISSN: 00016055
Type: Departmental Bulletin Paper
Text Version: publisher
Appears in Collections:Volume 48, No. 3-4

Citable URI : http://hdl.handle.net/10069/16250

All items in NAOSITE are protected by copyright, with all rights reserved.


Valid XHTML 1.0! Copyright © 2006-2015 Nagasaki University Library - Feedback Powerd by DSpace