title: Retinal expression and localization of Mef2c support its important role in photoreceptor gene expression.
abstract: Photoreceptor-specific gene expression is controlled by a hierarchical network of transcription factors, including the master regulators cone-rod homeobox (Crx) and neural retina leucine zipper (Nrl). Myocyte-enhancer factor 2c (Mef2c) is an ubiquitously expressed transcription factor with important functions in the cardiovascular system. Here, we performed a detailed analysis of Mef2c expression, localization and function in the retina to further elucidate its potential role for photoreceptor gene regulation. We showed that murine retinal Mef2c mRNA expression was high at birth and peaked at late postnatal developmental stages. Using immunohistochemistry and Western blot, Mef2c protein was detected in the outer nuclear layer of adult mouse and human retinas and localized to the nucleus of 661W photoreceptor-like cells. Mef2c knock-down in 661W cells reduced the expression of arrestin 3 (Arr3) and medium-wave-sensitive cone opsin (Opn1mw) but increased transcript levels of mitogen-activated protein kinase 15 (Mapk15) and phosphodiesterase 6h (Pde6h). In conclusion, Mef2c is highly expressed in the retina where it modulates photoreceptor-specific gene expression.
authors.affiliation: Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Wolf
authors.affiliation: Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Aslanidis
authors.affiliation: Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany. Electronic address: thomas.langmann@uk-koeln.de.
authors.forename: Thomas
authors.initials: T
authors.lastname: Langmann
mesh_terms: D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000378:metabolism; D000818:Animals; D019390:Arrestins / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6 / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D064326:MEF2 Transcription Factors / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D034741:RNA, Small Interfering / Q000378:metabolism; D012160:Retina / Q000378:metabolism*; D014018:Tissue Distribution
chemical_list: D019390:Arrestins; D064326:MEF2 Transcription Factors; C578040:MEF2C protein, human; C578041:Mef2c protein, mouse; D034741:RNA, Small Interfering; C000607304:arrestin 4 protein, mouse; C082333:arrestin3; D048049:Extracellular Signal-Regulated MAP Kinases; C456320:MAPK15 protein, human; C000619946:mitogen-activated protein kinase 15, mouse; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; C576560:PDE6H protein, human; C000619947:Pde6h protein, mouse
keywords: Gene regulation; Mef2c; Photoreceptors; Retina; Transcription factors