Myomegalin is a novel protein of the golgi/centrosome that interacts with a cyclic nucleotide phosphodiesterase.

Bibliographic Collection: 
MOCA Reference, APE
Publication Type: Journal Article
Authors: Verde, I; Pahlke, G; Salanova, M; Zhang, G; Wang, S; Coletti, D; Onuffer, J; Jin, S L; Conti, M
Year of Publication: 2001
Journal: J Biol Chem
Volume: 276
Issue: 14
Pagination: 11189-98
Date Published: 04/2001
Publication Language: eng
ISSN: 0021-9258
Keywords: 3',5'-Cyclic-AMP Phosphodiesterases, Amino Acid Sequence, Animals, Centrosome, Drosophila, Golgi Apparatus, Immunohistochemistry, Microtubule-Associated Proteins, Molecular Sequence Data, Organ Specificity, Protein Binding, Proteins, Rats, Saccharomyces cerevisiae, Sequence Analysis

Subcellular targeting of the components of the cAMP-dependent pathway is thought to be essential for intracellular signaling. Here we have identified a novel protein, named myomegalin, that interacts with the cyclic nucleotide phosphodiesterase PDE4D, thereby targeting it to particulate structures. Myomegalin is a large 2,324-amino acid protein mostly composed of alpha-helical and coiled-coil structures, with domains shared with microtubule-associated proteins, and a leucine zipper identical to that found in the Drosophila centrosomin. Transcripts of 7.5-8 kilobases were present in most tissues, whereas a short mRNA of 2.4 kilobases was detected only in rat testis. A third splicing variant was expressed predominantly in rat heart. Antibodies against the deduced sequence recognized particulate myomegalin proteins of 62 kDa in testis and 230-250 kDa in heart and skeletal muscle. Immunocytochemistry and transfection studies demonstrate colocalization of PDE4D and myomegalin in the Golgi/centrosomal area of cultured cells, and in sarcomeric structures of skeletal muscle. Myomegalin expressed in COS-7 cells coimmunoprecipitated with PDE4D3 and sequestered it to particulate structures. These findings indicate that myomegalin is a novel protein that functions as an anchor to localize components of the cAMP-dependent pathway to the Golgi/centrosomal region of the cell.

DOI: 10.1074/jbc.M006546200
Alternate Journal: J. Biol. Chem.