A novel interaction between lamin A and SREBP1: implications for partial lipodystrophy and other laminopathies
Abstract
The gene encoding nuclear lamins A and C is mutated in at least three inherited disorders. Two of these, Emery-Dreifuss muscular dystrophy (EDMD-AD) and a form of dilated cardiomyopathy (CMD1A), involve muscle defects, and the other, familial partial lipodystrophy (FPLD), involves loss of subcutaneous adipose tissue. Mutations causing FPLD, in contrast to those causing muscle disorders, are tightly clustered within the C-terminal domain of lamin A/C. We investigated the expression and subcellular localization of FPLD lamin A mutants and found no abnormalities. We therefore set out to identify proteins interacting with the C-terminal domain of lamin A by screening a mouse 3T3-L1 adipocyte library in a yeast two-hybrid interaction screen. Using this approach, the adipocyte differentiation factor, sterol response element binding protein 1 (SREBP1) was identified as a novel lamin A interactor. In vitro glutathione S-transferase pull-down and in vivo co-immunoprecipitation studies confirmed an interaction between lamin A and both SREBP1a and 1c. A binding site for lamin A was identified in the N-terminal transcription factor domain of SREBP1, between residues 227 and 487. The binding of lamin A to SREBP1 was noticeably reduced by FP...Continue Reading
Citations
LMNA variants cause cytoplasmic distribution of nuclear pore proteins in Drosophila and human muscle
Defects in nuclear structure and function promote dilated cardiomyopathy in lamin A/C-deficient mice
Related Concepts
Related Feeds
Cardiomyopathy
Cardiomyopathy is a disease of the heart muscle, that can lead to muscular or electrical dysfunction of the heart. It is often an irreversible disease that is associated with a poor prognosis. There are different causes and classifications of cardiomyopathies. Here are the latest discoveries pertaining to this disease.