Anchoring nuclei to the cytoskeleton

The adult Caenorhabditis elegans worm is covered by four large syncytial hypodermal cells that contain over 100 nuclei evenly spaced throughout the syncytia. Mutations in the anc-1 or unc-84 genes cause the Anc phenotype in which these nuclei either float freely within the cytoplasm or are grouped together. In the October 11 Science Daniel Starr and Min Han describe characterisation of the ANC-1 protein (Science, 298:406-409, October 11, 2002).

Starr and Han cloned the anc-1 gene, which encodes a large protein containing mostly predicted coiled regions. The C-terminus contains a KASH domain found in the Drosophila Klarsicht protein and mammalian Syne (synaptic nuclei expressed) proteins. The N-terminus contains an actin-binding domain similar to that found in Msp-300 and Syne proteins. Antibodies against ANC-1 revealed that localization in the nuclear periphery is disrupted in unc-84 mutants. Overexpression of a C-terminal fragment of ANC-1 caused a nuclear anchorage defect. Overexpression of high ...