The Caenorhabditis elegans SUN protein UNC-84 interacts with lamin to transfer forces from the cytoplasm to the nucleoskeleton during nuclear migration
نویسندگان
چکیده
Nuclear migration is a critical component of many cellular and developmental processes. The nuclear envelope forms a barrier between the cytoplasm, where mechanical forces are generated, and the nucleoskeleton. The LINC complex consists of KASH proteins in the outer nuclear membrane and SUN proteins in the inner nuclear membrane that bridge the nuclear envelope. How forces are transferred from the LINC complex to the nucleoskeleton is poorly understood. The Caenorhabditis elegans lamin, LMN-1, is required for nuclear migration and interacts with the nucleoplasmic domain of the SUN protein UNC-84. This interaction is weakened by the unc-84(P91S) missense mutation. These mutant nuclei have an intermediate nuclear migration defect-live imaging of nuclei or LMN-1::GFP shows that many nuclei migrate normally, others initiate migration before subsequently failing, and others fail to begin migration. At least one other component of the nucleoskeleton, the NET5/Samp1/Ima1 homologue SAMP-1, plays a role in nuclear migration. We propose a nut-and-bolt model to explain how forces are dissipated across the nuclear envelope during nuclear migration. In this model, SUN/KASH bridges serve as bolts through the nuclear envelope, and nucleoskeleton components LMN-1 and SAMP-1 act as both nuts and washers on the inside of the nucleus.
منابع مشابه
Lamin-dependent localization of UNC-84, a protein required for nuclear migration in Caenorhabditis elegans.
Mutations in the Caenorhabditis elegans unc-84 gene cause defects in nuclear migration and anchoring. We show that endogenous UNC-84 protein colocalizes with Ce-lamin at the nuclear envelope and that the envelope localization of UNC-84 requires Ce-lamin. We also show that during mitosis, UNC-84 remains at the nuclear periphery until late anaphase, similar to known inner nuclear membrane protein...
متن کاملLINC complexes promote homologous recombination in part through inhibition of nonhomologous end joining
The Caenorhabditis elegans SUN domain protein, UNC-84, functions in nuclear migration and anchorage in the soma. We discovered a novel role for UNC-84 in DNA damage repair and meiotic recombination. Loss of UNC-84 leads to defects in the loading and disassembly of the recombinase RAD-51. Similar to mutations in Fanconi anemia (FA) genes, unc-84 mutants and human cells depleted of Sun-1 are sens...
متن کاملThe SUN protein UNC-84 is required only in force-bearing cells to maintain nuclear envelope architecture
The nuclear envelope (NE) consists of two evenly spaced bilayers, the inner and outer nuclear membranes. The Sad1p and UNC-84 (SUN) proteins and Klarsicht, ANC-1, and Syne homology (KASH) proteins that interact to form LINC (linker of nucleoskeleton and cytoskeleton) complexes connecting the nucleoskeleton to the cytoskeleton have been implicated in maintaining NE spacing. Surprisingly, the NE ...
متن کاملunc-83 encodes a novel component of the nuclear envelope and is essential for proper nuclear migration.
Nuclear migration plays an essential role in the growth and development of a wide variety of eukaryotes. Mutations in unc-84, which encodes a conserved component of the nuclear envelope, have been shown to disrupt nuclear migration in two C. elegans tissues. We show that mutations in unc-83 disrupt nuclear migration in a similar manner in migrating P cells, hyp7 precursors and the intestinal pr...
متن کاملUNC-83 IS a KASH protein required for nuclear migration and is recruited to the outer nuclear membrane by a physical interaction with the SUN protein UNC-84.
UNC-84 is required to localize UNC-83 to the nuclear envelope where it functions during nuclear migration. A KASH domain in UNC-83 was identified. KASH domains are conserved in the nuclear envelope proteins Syne/nesprins, Klarsicht, MSP-300, and ANC-1. Caenorhabditis elegans UNC-83 was shown to localize to the outer nuclear membrane and UNC-84 to the inner nuclear membrane in transfected mammal...
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عنوان ژورنال:
دوره 25 شماره
صفحات -
تاریخ انتشار 2014