The muscle ankyrin repeat proteins: CARP, ankrd2/Arpp and DARP as a family of titin filament-based stress response molecules.
CARP, ankrd-2/Arpp, and DARP, are three members of a conserved gene family, referred to here as MARPs (muscle ankyrin repeat proteins). The expression of MARPs is induced upon injury and hypertrophy (CARP), stretch or denervation (ankrd2/Arpp), and during recovery following starvation (DARP), suggesting that they are involved in muscle stress ... response pathways. Here, we show that MARP family members contain within their ankyrin repeat region a binding site for the myofibrillar elastic protein titin. Within the myofibril, MARPs, myopalladin, and the calpain protease p94 appear to be components of a titin N2A-based signaling complex. Ultrastructural studies demonstrated that all three endogenous MARP proteins co-localize with I-band titin N2A epitopes in adult heart muscle tissues. In cultured fetal rat cardiac myocytes, passive stretch induced differential distribution patterns of CARP and DARP: staining for both proteins was increased in the nucleus and at the I-band region of myofibrils, while DARP staining also increased at intercalated discs. We speculate that the myofibrillar MARPs are regulated by stretch, and that this links titin-N2A-based myofibrillar stress/strain signals to a MARP-based regulation of muscle gene expression.
Mesh Terms:
Amino Acid Motifs, Amino Acid Sequence, Base Sequence, Conserved Sequence, Humans, Molecular Sequence Data, Muscle Proteins, Muscle, Skeletal, Myocardium, Nuclear Proteins, Protein Kinases, Repressor Proteins
Amino Acid Motifs, Amino Acid Sequence, Base Sequence, Conserved Sequence, Humans, Molecular Sequence Data, Muscle Proteins, Muscle, Skeletal, Myocardium, Nuclear Proteins, Protein Kinases, Repressor Proteins
J. Mol. Biol.
Date: Nov. 07, 2003
PubMed ID: 14583192
View in: Pubmed Google Scholar
Download Curated Data For This Publication
7660
Switch View:
- Interactions 12