Sequestration of pRb by cyclin D3 causes intranuclear reorganization of lamin A/C during muscle cell differentiation

Mariappan, Indumathi ; Parnaik, Veena K. (2005) Sequestration of pRb by cyclin D3 causes intranuclear reorganization of lamin A/C during muscle cell differentiation Molecular Biology of the Cell, 16 (4). pp. 1948-1960. ISSN 1059-1524

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Official URL: http://www.molbiolcell.org/cgi/content/abstract/16...

Related URL: http://dx.doi.org/10.1091/mbc.E04-02-0154

Abstract

The A-type lamins that localize in nuclear domains termed lamin speckles are reorganized and antigenically masked specifically during myoblast differentiation. This rearrangement was observed to be linked to the myogenic program as lamin speckles, stained with monoclonal antibody (mAb) LA-2H10, were reorganized in MyoD-transfected fibroblasts induced to transdifferentiate to muscle cells. In C2C12 myoblasts, speckles were reorganized early during differentiation in cyclin D3-expressing cells. Ectopic cyclin D3 induced lamin reorganization in C2C12 myoblasts but not in other cell types. Experiments with adenovirus E1A protein that can bind to and segregate the retinoblastoma protein (pRb) indicated that pRb was essential for the cyclin D3-mediated reorganization of lamin speckles. Cyclin D3-expressing myoblasts displayed site-specific reduction of pRb phosphorylation. Furthermore, disruption of lamin structures by overexpression of lamins inhibited expression of the muscle regulatory factor myogenin. Our results suggest that the reorganization of internal lamins in muscle cells is mediated by key regulators of the muscle differentiation program.

Item Type:Article
Source:Copyright of this article belongs to American Society for Cell Biology.
ID Code:34719
Deposited On:11 Apr 2011 14:08
Last Modified:17 May 2016 17:36

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