High impact information on nuc2

• In nda3 and cut7 mutants defective in tubulin of a kinesin-related motor, cells are blocked in early stages of mitosis due to the absence of the spindle, and centromeres dissociate but remain close to the SPB, whereas in a metaphase-arrested nuc2 mutant, they reside at the middle of the spindle [1].
• At the restrictive temperature, nuc2 cells are arrested at a metaphase-like stage with short spindles and condensed chromosomes [2].
• This suggests that the nuc2 cells are impaired in function at a stage before sister chromatid disjunction [2].
• A temperature-sensitive mutation of the Schizosaccharomyces pombe gene nuc2+ that encodes a nuclear scaffold-like protein blocks spindle elongation in mitotic anaphase [3].
• The nuc2' gene was cloned in a 2.4-kb genomic DNA fragment by transformation, and its complete nucleotide sequence was determined [3].

Biological context of nuc2

• The role of nuc2+ gene may be to interconnect nuclear and cytoskeletal functions in chromosome separation [3].
• By immunoblots using anti-sera raised against lacZ-nuc2+ fused proteins, a polypeptide (designated p67; 67,000 mol wt) encoded by nuc2+ is detected in the wild-type S. pombe extracts; the amount of p67 is greatly increased when multi-copy or high-expression plasmids carrying the nuc2+ gene are introduced into the S. pombe cells [3].
• In this study, we present evidence which shows that nuc2 has two additional roles in the cell cycle [4].
• Therefore, the nuc2 mutant is deficient only for failure to block DNA replication upon starvation [4].
• At the lower restrictive temperature, the nuc2 mutant showed a 'cut' phenotype where septation and cytokinesis takes place without the completion of mitosis [4].

References