Crystal structure of the catalytic subunit of Cdc25B required for G 2 /M phase transition of the cell cycle 1 1Edited by I. A. Wilson

We have investigated whether Plx1, a kinase recently shown to phosphorylate cdc25c in vitro, is required for activation of cdc25c at the G2/M-phase transition of the cell cycle in Xenopus. Using immunodepletion or the mere addition of an antibody against the C terminus of Plx1, which suppressed its activation (not its activity) at G2/M, we show that Plx1 activity is required for activation of cyclin B-cdc2 kinase in both interphase egg extracts receiving recombinant cyclin B, and cycling extracts that spontaneously oscillate between interphase and mitosis. Furthermore, a positive feedback loop allows cyclin B-cdc2 kinase to activate Plx1 at the G2/M-phase transition. In contrast, activation of cyclin A-cdc2 kinase does not require Plx1 activity, and cyclin A-cdc2 kinase fails to activate Plx1 and its consequence, cdc25c activation in cycling extracts.

Download Full-text

Abstract 3817: Nitric oxide-donating aspirin induces G2/M phase cell cycle arrest in human cancer cells by regulating phase transition proteins

10.1158/1538-7445.am2012-3817 ◽

2012 ◽

Author(s):

Li Gao ◽

Jennie L. Williams

Keyword(s):

Nitric Oxide ◽

Phase Transition ◽

Cell Cycle ◽

Cell Cycle Arrest ◽

Cancer Cells ◽

Human Cancer ◽

Phase Cell ◽

Human Cancer Cells ◽

Cycle Arrest ◽

M Phase

Download Full-text

Periodic biosynthesis of the human M-phase promoting factor catalytic subunit p34 during the cell cycle

Molecular and Cellular Biology ◽

10.1128/mcb.10.7.3847-3851.1990 ◽

1990 ◽

Vol 10 (7) ◽

pp. 3847-3851

Author(s):

C H McGowan ◽

P Russell ◽

S I Reed

Keyword(s):

Cell Cycle ◽

Protein Kinase ◽

Hela Cells ◽

Catalytic Subunit ◽

Dependent Manner ◽

Reversible Phosphorylation ◽

M Phase ◽

A Cell ◽

Cycle Dependent

The product of the CDC2Hs gene is the protein kinase subunit of the M-phase promoting factor, which is required for entry into mitosis. The activity of this kinase is regulated in a cell cycle-dependent manner by reversible phosphorylation and through association with other proteins. We report here that in HeLa cells, the abundance of the CDC2Hs mRNA and the rate of synthesis of the encoded protein, p34, vary in a cell cycle-dependent manner.

Download Full-text

Indirect semiquantitative determination of p34cdc2 levels in G1 and G2 cells of the carbohydrate-starved root meristems in Vicia faba var. minor

Acta Societatis Botanicorum Poloniae ◽

10.5586/asbp.1999.034 ◽

2014 ◽

Vol 68 (4) ◽

pp. 255-259 ◽

Cited By ~ 2

Author(s):

Justyna Polit

Keyword(s):

Phase Transition ◽

Cell Cycle ◽

Vicia Faba ◽

Absolute Level ◽

Cycle Enzyme ◽

Meristematic Cells ◽

Semiquantitative Determination ◽

M Phase ◽

Cell Cycle Block

In eukaryotes, the 34kDa kinase (p34) encoded by the cdc2 gene is a key regulator of both the onset of DNA synthesis (G1 to S phase transition) and the onset of mitosis (G1 to M phase transition). Using mouse anti-human PSTAIRE and FITClabelled goat antibodies, indirect semiquantitative determination of p34cdc2 levels was performed in meristematic cells from the control (intact) and excised, carbohydrate-starved main roots of Vicia faba var. minor. No evident differences in the intensity of fluorescence was found either between the G1 and G2 cells or between the control cells and the cells arrested at both Principal Control Points by carbohydrate starvation. It seems thus, that the cell cycle block induced in meristematic cells of V. faba var. minor is not correlated with the absolute level of the key cell cycle enzyme responsible for phosphory-lution of cellular proteins, but primarily with the altered activity of p34cdc2.

Download Full-text

Lamprey Prohibitin2 Arrest G2/M Phase Transition of HeLa Cells through Down-regulating Expression and Phosphorylation Level of Cell Cycle Proteins

Scientific Reports ◽

10.1038/s41598-018-22212-0 ◽

2018 ◽

Vol 8 (1) ◽

Cited By ~ 1

Author(s):

Ying Shi ◽

Sicheng Guo ◽

Ying Wang ◽

Xin Liu ◽

Qingwei Li ◽

...

Keyword(s):

Phase Transition ◽

Cell Cycle ◽

Hela Cells ◽

Cell Cycle Proteins ◽

Phosphorylation Level ◽

M Phase

Download Full-text

Nuclear Accumulation of p21Cip1 at the Onset of Mitosis: a Role at the G2/M-Phase Transition

Molecular and Cellular Biology ◽

10.1128/mcb.18.1.546 ◽

1998 ◽

Vol 18 (1) ◽

pp. 546-557 ◽

Cited By ~ 245

Author(s):

Vjekoslav Dulić ◽

Gretchen H. Stein ◽

Dariush Farahi Far ◽

Steven I. Reed

Keyword(s):

Phase Transition ◽

Cell Cycle ◽

Nuclear Translocation ◽

Cyclin A ◽

Cyclin B1 ◽

Negative Control ◽

Cell Cycle Checkpoint ◽

Nuclear Accumulation ◽

E6 Oncoprotein ◽

M Phase

ABSTRACT Cell cycle arrest in G1 in response to ionizing radiation or senescence is believed to be provoked by inactivation of G1 cyclin-cyclin-dependent kinases (Cdks) by the Cdk inhibitor p21Cip1/Waf1/Sdi1. We provide evidence that in addition to exerting negative control of the G1/S phase transition, p21 may play a role at the onset of mitosis. In nontransformed fibroblasts, p21 transiently reaccumulates in the nucleus near the G2/M-phase boundary, concomitant with cyclin B1 nuclear translocation, and associates with a fraction of cyclin A-Cdk and cyclin B1-Cdk complexes. Premitotic nuclear accumulation of cyclin B1 is not detectable in cells with low p21 levels, such as fibroblasts expressing the viral human papillomavirus type 16 E6 oncoprotein, which functionally inactivates p53, or in tumor-derived cells. Moreover, synchronized E6-expressing fibroblasts show accelerated entry into mitosis compared to wild-type cells and exhibit higher cyclin A- and cyclin B1-associated kinase activities. Finally, primary embryonic fibroblasts derived from p21−/− mice have significantly reduced numbers of premitotic cells with nuclear cyclin B1. These data suggest that p21 promotes a transient pause late in G2 that may contribute to the implementation of late cell cycle checkpoint controls.

Download Full-text

Periodic biosynthesis of the human M-phase promoting factor catalytic subunit p34 during the cell cycle.

Molecular and Cellular Biology ◽

10.1128/mcb.10.7.3847 ◽

1990 ◽

Vol 10 (7) ◽

pp. 3847-3851 ◽

Cited By ~ 56

Author(s):

C H McGowan ◽

P Russell ◽

S I Reed

Keyword(s):

Cell Cycle ◽

Protein Kinase ◽

Hela Cells ◽

Catalytic Subunit ◽

Dependent Manner ◽

Reversible Phosphorylation ◽

M Phase ◽

A Cell ◽

Cycle Dependent

The product of the CDC2Hs gene is the protein kinase subunit of the M-phase promoting factor, which is required for entry into mitosis. The activity of this kinase is regulated in a cell cycle-dependent manner by reversible phosphorylation and through association with other proteins. We report here that in HeLa cells, the abundance of the CDC2Hs mRNA and the rate of synthesis of the encoded protein, p34, vary in a cell cycle-dependent manner.

Download Full-text