First Author | Bengtsson L | Year | 2008 |
Journal | J Cell Sci | Volume | 121 |
Issue | Pt 4 | Pages | 536-48 |
PubMed ID | 18230648 | Mgi Jnum | J:138280 |
Mgi Id | MGI:3804743 | Doi | 10.1242/jcs.019281 |
Citation | Bengtsson L, et al. (2008) LUMA interacts with emerin and influences its distribution at the inner nuclear membrane. J Cell Sci 121(Pt 4):536-48 |
abstractText | We present here a first characterization of LUMA, an unique integral inner nuclear membrane (INM) protein. LUMA is a highly conserved protein even in some bacteria and shares a PFAM domain of unknown function with orthologs from many species. Assessing LUMA topology by using protease protection of membrane-inserted LUMA and antibody epitope accessibility assays reveals that LUMA contains four transmembrane domains and a large hydrophilic domain located between membrane spans 1 and 2. The large hydrophilic domain is exposed to the perinuclear space whereas both LUMA termini reside cyto- or nucleoplasmically. Nuclear envelope targeting of LUMA mainly depends on the membrane spans. LUMA's transmembrane domains also promote homooligomerization. LUMA binds A- and B-type lamins and depends on A-type lamins for its INM localization. Furthermore, it interacts with emerin. Both downregulation of LUMA and overexpression of dominant-negative acting LUMA fragments causes redistribution of emerin. We propose that LUMA functions as a tetraspanin-like membrane organizer and has the potential to contribute to the pathomechanism of dystrophic diseases, such as Emery-Dreifuss muscular dystrophy. |