Myomegalin
Myomegalin, also known as phosphodiesterase 4D-interacting protein or cardiomyopathy-associated protein 2, is a protein that in humans is encoded by the PDE4DIP gene.[5][6][7] It has roles in the formation of microtubules from the centrosome.[8] Its name derives from the fact that it is highly expressed in units of tubular myofibrils known as sarcomeres and is a large protein, at 2,324 amino acids.[9] It was first characterised in 2000.[9]
Structure and function
Myomegalin is mostly composed of alpha-helix and coiled-coil structures and has domains shared with microtubule-associated proteins.[9] It has several isoforms, at least two of which have been characterised, CM-MMG and EB-MMG.[8]
Myomegalin is necessary for the sufficient growth of microtubules from the centrosomes. The CM-MMG isoform binds at the centrosome with γ-tubulin in an AKAP9-dependent manner and on the near side of the Golgi apparatus, while the EB-MMG isoform binds with MAPRE1 at the Golgi apparatus and increases MAPRE1's effects on microtubule growth.[8]
Myomegalin, specifically the CM-MMG isoform, is a paralogue of CDK5RAP2.[8][10][11] Myomegalin depletion in cells does not lead to decreases in γ-tubulin or CDK5RAP2, unlike CDK5RAP2 depletion, and does not appear to affect mitosis through various spindle anchoring and orientation defects, unlike CDK5RAP2. This indicates that CDK5RAP2 can somewhat serve to compensate for the absence of myomegalin. However, myomegalin-depleted cells have slower migration, since microtubules are crucial for cell motility.[8]
Orthologues of myomegalin are seen in vertebrates as far back as bony fish, around 450 million years ago. In mammals, around 200 million years ago, myomegalin gained an Olduvai domain. Olduvai domains have so far only elsewhere been found in NBPF genes in placental mammals, many of which are adjacent to myomegalin on chromosome 1, so it is believed that these genes originated from a duplication of myomegalin.[12] Increased NPBF Olduvai domain duplications in humans have been implicated in human brain size evolution.[13]
History
The protein was discovered in 2000 and was so named because it was highly expressed in rat heart muscle sarcomeres (units of tubular myofibrils) and is a large protein, at 2,324 amino acids.[9]
References
- GRCh38: Ensembl release 89: ENSG00000178104 - Ensembl, May 2017
- GRCm38: Ensembl release 89: ENSMUSG00000038170 - Ensembl, May 2017
- "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
- Seki N, Ohira M, Nagase T, Ishikawa K, Miyajima N, Nakajima D, et al. (October 1997). "Characterization of cDNA clones in size-fractionated cDNA libraries from human brain". DNA Research. 4 (5): 345–9. doi:10.1093/dnares/4.5.345. PMID 9455484.
- Verde I, Pahlke G, Salanova M, Zhang G, Wang S, Coletti D, et al. (April 2001). "Myomegalin is a novel protein of the golgi/centrosome that interacts with a cyclic nucleotide phosphodiesterase". The Journal of Biological Chemistry. 276 (14): 11189–98. doi:10.1074/jbc.M006546200. PMID 11134006.
- "Entrez Gene: PDE4DIP phosphodiesterase 4D interacting protein (myomegalin)".
- Roubin R, Acquaviva C, Chevrier V, Sedjaï F, Zyss D, Birnbaum D, Rosnet O (February 2013). "Myomegalin is necessary for the formation of centrosomal and Golgi-derived microtubules". Biology Open. 2 (2): 238–50. doi:10.1242/bio.20123392. PMC 3575658. PMID 23430395.
- Verde I, Pahlke G, Salanova M, Zhang G, Wang S, Coletti D, et al. (April 2001). "Myomegalin is a novel protein of the golgi/centrosome that interacts with a cyclic nucleotide phosphodiesterase". The Journal of Biological Chemistry. 276 (14): 11189–98. doi:10.1074/jbc.M006546200. PMID 11134006.
- Dumas L, Kim YH, Karimpour-Fard A, Cox M, Hopkins J, Pollack JR, Sikela JM (September 2007). "Gene copy number variation spanning 60 million years of human and primate evolution". Genome Research. 17 (9): 1266–77. doi:10.1101/gr.6557307. PMC 1950895. PMID 17666543.
- O'Bleness MS, Dickens CM, Dumas LJ, Kehrer-Sawatzki H, Wyckoff GJ, Sikela JM (September 2012). "Evolutionary history and genome organization of DUF1220 protein domains". G3. 2 (9): 977–86. doi:10.1534/g3.112.003061. PMC 3429928. PMID 22973535.
- O'Bleness MS, Dickens CM, Dumas LJ, Kehrer-Sawatzki H, Wyckoff GJ, Sikela JM (September 2012). "Evolutionary history and genome organization of DUF1220 protein domains". G3. 2 (9): 977–86. doi:10.1534/g3.112.003061. PMC 3429928. PMID 22973535.
- Sikela JM, van Roy F (2018). "Changing the name of the NBPF/DUF1220 domain to the Olduvai domain". F1000Research. 6 (2185): 2185. doi:10.12688/f1000research.13586.1. PMC 5773923. PMID 29399325.
Further reading
- Soejima H, Kawamoto S, Akai J, Miyoshi O, Arai Y, Morohka T, et al. (May 2001). "Isolation of novel heart-specific genes using the BodyMap database". Genomics. 74 (1): 115–20. doi:10.1006/geno.2001.6527. PMID 11374908.
- Suzuki Y, Yamashita R, Shirota M, Sakakibara Y, Chiba J, Mizushima-Sugano J, et al. (September 2004). "Sequence comparison of human and mouse genes reveals a homologous block structure in the promoter regions". Genome Research. 14 (9): 1711–8. doi:10.1101/gr.2435604. PMC 515316. PMID 15342556.
- Kimura K, Wakamatsu A, Suzuki Y, Ota T, Nishikawa T, Yamashita R, et al. (January 2006). "Diversification of transcriptional modulation: large-scale identification and characterization of putative alternative promoters of human genes". Genome Research. 16 (1): 55–65. doi:10.1101/gr.4039406. PMC 1356129. PMID 16344560.
- Lim J, Hao T, Shaw C, Patel AJ, Szabó G, Rual JF, et al. (May 2006). "A protein-protein interaction network for human inherited ataxias and disorders of Purkinje cell degeneration". Cell. 125 (4): 801–14. doi:10.1016/j.cell.2006.03.032. PMID 16713569.
- Shimada H, Kuboshima M, Shiratori T, Nabeya Y, Takeuchi A, Takagi H, et al. (January 2007). "Serum anti-myomegalin antibodies in patients with esophageal squamous cell carcinoma". International Journal of Oncology. 30 (1): 97–103. doi:10.3892/ijo.30.1.97. PMID 17143517.