Weingartner M, Binarova P, Drykova D, Schweighofer A, David JP, Heberle-Bors E, Doonan J, Bögre L. Dynamic recruitment of Cdc2 to specific microtubule structures during mitosis.
THE PLANT CELL 2001. [PMID:
11487703 DOI:
10.1105/tpc.13.8.1929]
[Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A-type cyclin-dependent kinases (CDKs), also known as cdc2, are central to the orderly progression of the cell cycle. We made a functional Green Fluorescent Protein (GFP) fusion with CDK-A (Cdc2-GFP) and followed its subcellular localization during the cell cycle in tobacco cells. During interphase, the Cdc2-GFP fusion protein was found in both the cytoplasm and the nucleus, where it was highly resistant to extraction. In premitotic cells, a bright and narrow equatorial band appeared on the cell surface, resembling the late preprophase band, which disintegrated within 10 min as followed by time-lapse images. Cdc2-GFP was not found on prophase spindles but left the chromatin soon after this stage and associated progressively with the metaphase spindle in a microtubule-dependent manner. Arresting cells in mitosis through the stabilization of microtubules by taxol further enhanced the spindle-localized pool of Cdc2-GFP. Toward the end of mitosis, Cdc2-GFP was found at the midzone of the anaphase spindle and phragmoplast; eventually, it became focused at the midline of these microtubule structures. In detergent-extracted cells, the Cdc2-GFP remained associated with mitotic structures. Retention on spindles was prevented by pretreatment with the CDK-specific inhibitor roscovitine and was enhanced by the protein phosphatase inhibitor okadaic acid. Furthermore, we demonstrate that both the endogenous CDK-A and Cdc2-GFP were cosedimented with taxol-stabilized plant microtubules from cell extracts and that Cdc2 activity was detected together with a fraction of polymerized tubulin. These data provide evidence that the A-type CDKs associate physically with mitotic structures in a microtubule-dependent manner and may be involved in regulating the behavior of specific microtubule arrays throughout mitosis.
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