First Author | Haque F | Year | 2006 |
Journal | Mol Cell Biol | Volume | 26 |
Issue | 10 | Pages | 3738-51 |
PubMed ID | 16648470 | Mgi Jnum | J:109072 |
Mgi Id | MGI:3625669 | Doi | 10.1128/MCB.26.10.3738-3751.2006 |
Citation | Haque F, et al. (2006) SUN1 interacts with nuclear lamin A and cytoplasmic nesprins to provide a physical connection between the nuclear lamina and the cytoskeleton. Mol Cell Biol 26(10):3738-51 |
abstractText | Nuclear migration and positioning within cells are critical for many developmental processes and are governed by the cytoskeletal network. Although mechanisms of nuclear-cytoskeletal attachment are unclear, growing evidence links a novel family of nuclear envelope (NE) proteins that share a conserved C-terminal SUN (Sad1/UNC-84 homology) domain. Analysis of Caenorhabditis elegans mutants has implicated UNC-84 in actin-mediated nuclear positioning by regulating NE anchoring of a giant actin-binding protein, ANC-1. Here, we report the identification of SUN1 as a lamin A-binding protein in a yeast two-hybrid screen. We demonstrate that SUN1 is an integral membrane protein located at the inner nuclear membrane. While the N-terminal domain of SUN1 is responsible for detergent-resistant association with the nuclear lamina and lamin A binding, lamin A/C expression is not required for SUN1 NE localization. Furthermore, SUN1 does not interact with type B lamins, suggesting that NE localization is ensured by binding to an additional nuclear component(s), most likely chromatin. Importantly, we find that the luminal C-terminal domain of SUN1 interacts with the mammalian ANC-1 homologs nesprins 1 and 2 via their conserved KASH domain. Our data provide evidence of a physical nuclear-cytoskeletal connection that is likely to be a key mechanism in nuclear-cytoplasmic communication and regulation of nuclear position. |