An evolutionarily conserved gene required for proper microtubule architecture in Caenorhabditis elegans.

Microtubules are involved in many cellular events during the cell cycle and also in a variety of early embryonic developmental processes. Their architecture and properties change dramatically during the cell cycle and are properly regulated. However, these regulatory mechanisms have not been fully elucidated. C05D11.3 gene of Caenorhabditis elegans encodes a low molecular weight protein that is evolutionarily conserved from yeasts to mammals. A mouse homolog of the C05D11.3 product, APACD (ATP binding protein associated with cell differentiation), contains a thioredoxin-like domain and P-loop, and is present in both the nucleus and the cytoplasm, showing often localization to centrosomes and midbody. In C. elegans, C05D11.3 is expressed throughout development with higher levels of expression in most cells of the nervous system and in vulva. C05D11.3 RNAi-treated embryos show apparent defects in pronuclear migration or nuclear-centrosome rotation, and exhibit little astral microtubules and defective small spindles. These results indicate that C05D11.3, an evolutionarily conserved gene, is essential for proper microtubule organization and function in C. elegans. This gene family may be a conserved regulator of microtubule dynamics and function.