Dimerization of the cardiac ankyrin protein CARP: Implications for MARP titin-based signaling
- 221 Downloads
Cardiac ankyrin repeat protein (CARP) and its two close homologs ankrd2 (Arpp) and DARP correspond to a conserved gene family of muscle ankyrin repeat proteins (MARPs). All three genes respond to a variety of stress/strain injury signals with their cytokine-like induction and can associate with the elastic region of titin/connectin. Recently, both CARP and ankrd2 were observed to be elevated in cardiac diseases as well as muscular dystrophies, implicating their joined signaling in muscle diseases. Here we show that CARP in the yeast two-hybrid system (YTH) interacts with itself and desmin. To further verify the YTH data and to investigate possible CARP subunit structure(s), we expressed CARP in E. coli. Expressed CARP has an apparent mobility of about 70 kDa on gel filtration, corresponding to a dimeric species. Yeast two-hybrid experiments using amino- and carboxyterminal deletion clones suggest that CARP, ankrd2, and DARP contain potential coiled-coil dimerization motifs within their unique aminoterminal domains that mediate the formation of homo-dimers. In contrast, we could not detect the formation of hetero-dimers between CARP, ankrd2, and DARP. Therefore, when CARP, ankrd2 and DARP are upregulated in disease/stress states, they are likely to be sorted into distinct structural protein complexes since CARP within the MARP family contains a unique aminoterminal dimerization motif.
KeywordsMuscular Dystrophy Ankyrin Repeat Congenital Muscular Dystrophy Limb Girdle Muscular Dystrophy Cardiac Ankyrin Repeat Protein
Unable to display preview. Download preview PDF.
The authors would like to thank Richard Carmouche from the EMBL gene core for expert technical assistance. This work was supported by the Deutsche Forschungsgemeinschaft (LA668/7-2 to SL and LA1969/1-1 to DL).
- Gregorio CC, Trombitas K, Centner T, Kolmerer B, Stier G, Kunke K, Suzuki K, Obermayer F, Herrmann B, Granzier H, Sorimachi H, Labeit S, (1998) The NH2 terminus of titin spans the Z-disc; Its interaction with a novel 19 kD ligand (T-cap) is required for sarcomeric integrity J Cell Biol 143:1013–1027PubMedCrossRefGoogle Scholar
- Ishiguro N, Baba T, Ishida T, Takeuchi K, Osaki M, Araki N, Okada E, Takahashi S, Saito M, Watanabe M, Nakada C, Tsukamoto Y, Sato K, Ito K, Fukayama M, Mori S, Ito H, Moriyama M. (2002) Carp, a cardiac ankyrin-repeated protein, and its new homologue, Arpp, are differentially expressed in heart, skeletal muscle, and rhabdomyosarcomas Am J Pathol 160:1767–1778PubMedGoogle Scholar
- Knöll R, Hoshijima M, Hoffman HM, Person V, Lorenzen-Schmidt I, Bang ML, Hayashi T, Shiga N, Yasukawa H, Schaper W, McKenna W, Yokoyama M, Schork NJ, Omens JH, McCulloch AD, Kimura A, Gregorio CC, Poller W, Schaper J, Schultheiss HP, Chien KR, (2002) The cardiac mechanical stretch sensor machinery involves a Z disc complex that is defective in a subset of human dilated cardiomyopathy Cell 111:943–955PubMedCrossRefGoogle Scholar
- Sorimachi H, Kinbara K, Kimura S, Takahashi M, Ishiura S, Sasagawa N, Sorimachi N, Shimada H, Tagawa K, Maruyama K, Suzuki K, (1995) Muscle-specific calpain, p94, responsible for limb girdle muscular dystrophy type 2A, associates with connectin through IS2, a p94-specific sequence J Biol Chem 270:31158–31162PubMedCrossRefGoogle Scholar
- Toko H, Zhu W, Takimoto E, Shiojima I, Hiroi Y, Zou Y, Oka T, Akazawa H, Mizukami M, Sakamoto M, Terasaki F, Kitaura Y, Takano H, Nagai T, Nagai R, Komuro I, (2002) Csx/Nkx2-5 is required for homeostasis and survival of cardiac myocytes in the adult heart J Biol Chem 277:24735–24743PubMedCrossRefGoogle Scholar
- Witt CC, Ono Y, Puschmann E, McNabb M, Wu Y, Gotthardt M, Witt SH, Haak M, Labeit D, Gregorio CC, Sorimachi H, Granzier H, Labeit S. (2004) Induction and myofibrillar targeting of CARP, and suppression of the Nkx2.5 pathway in the MDM mouse with impaired titin-based signaling J Mol Biol 336:145–154PubMedCrossRefGoogle Scholar