High TMEM45A expression is correlated to epidermal keratinization. Issue 5 (May 2014)

• Record Type: Journal Article
• Authors: Hayez, Aurélie; Malaisse, Jérémy; Roegiers, Edith; Reynier, Marie; Renard, Chantal; Haftek, Marek; Geenen, Vincent; Serre, Guy; Simon, Michel; de, Catherine Lambert; Michiels, Carine; Poumay, Yves
• Is Part Of: Experimental dermatology. Volume 23:Issue 5(2014:May)
• Page Start: 339
• Page End: 344
• Publication Date: 2014-05
• Subjects: Dermatology -- Periodicals; 616.5
• DOI: 10.1111/exd.12403
• Languages: English
• ISSNs: 0906-6705

Abstract

<abstract abstract-type="main" id="exd12403-abs-0002"> <title>Abstract</title> <p> <italic>TMEM45A</italic> (<italic>DERP7</italic>, <italic> DNAPTP4</italic> or <italic>FLJ10134</italic>) gene, belonging to the TMEM family encoding predicted transmembrane proteins, is highly expressed in epidermal keratinocytes. To investigate the potential involvement of TMEM45A during the differentiation and keratinization processes, its expression has been characterized in normal human keratinocytes and the protein subcellular localization has been studied in this cell type, both <italic>in vitro</italic> and <italic>in vivo</italic>. TMEM45A expression is upregulated with differentiation, either induced by cultured keratinocyte confluence or enhanced Ca<sup>2+</sup> concentration in medium. <italic>In vivo</italic>, TMEM45A mRNA and protein are mostly found in the granular layer of the epidermis. TMEM45A expression is linked to keratinization, as accumulation of the protein is detected in native and reconstructed epidermis as well as in thymic Hassal bodies, but not in non‐keratinized stratified epithelia. At the subcellular level, co‐detection with ER and Golgi markers reveals that TM protein 45A is associated with the Golgi apparatus and more specifically with the trans‐Golgi/trans‐Golgi network <italic>in vitro</italic> and in granular layer <italic>in vivo</italic>. The protein is neither related to lysosomes nor transported within corneodesmosin‐containing lamellar bodies. These data demonstrate a strong correlation between TMEM45A expression and epidermal keratinization, indicating the relevance of this gene in this process.</p> </abstract>