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The carboxy‐terminus of Alp4 alters microtubule dynamics to induce oscillatory nuclear movement led by the spindle pole body in Schizosaccharomyces pombe
Author(s) -
Masuda Hirohisa,
Miyamoto Rumi,
Haraguchi Tokuko,
Hiraoka Yasushi
Publication year - 2006
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1111/j.1365-2443.2006.00947.x
Subject(s) - biology , microtubule , microbiology and biotechnology , cytoplasm , dynein , kinesin , spindle pole body , schizosaccharomyces pombe , nuclear transport , nucleus , tubulin , oscillation (cell signaling) , cell nucleus , cell , cell division , genetics , spindle apparatus , saccharomyces cerevisiae , yeast
Alp4 is an essential component of the S. pombe γ‐tubulin complex. Overproduction of the carboxy‐terminus of Alp4 induces oscillatory nuclear movement led by the spindle pole body (SPB). The movement is not dependent on cytoplasmic dynein dhc1, or kinesin‐related proteins pkl1 and klp2. Rates of SPB movement correlate with elongation rates of microtubules (MTs) extending backwards from the moving SPB (backward‐extending MTs), showing that pushing forces exerted by backward‐extending MTs move the nucleus via the SPB. These backward‐extending MTs are more stable than those of control cells and, thus, are able to push the SPB further towards the cell end, inducing nuclear oscillation with larger amplitudes than in control cells. SPB movement is biased towards the new end of the cell where levels of the CLIP170 homolog Tip1 increase, suggesting that the movement is related to MT‐mediated cell polarity control. These results demonstrate that the carboxy‐terminus of Alp4 alters MT dynamics and induces nuclear oscillation by modulating a nuclear positioning mechanism based on the balance of MT pushing forces, and suggest that regulation of γ‐tubulin complex activity is important for controlling MT dynamics and nuclear positioning.