Centrin-2 Is Required for Centriole Duplication in Mammalian Cells

Salisbury, Jeffrey L.; Suino, Kelly M; Busby, Robert C.; Springett, Margaret J.

doi:10.1016/s0960-9822(02)01019-9

Cited by 284 publications

(258 citation statements)

References 46 publications

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“…The growth arrest response in cells lacking centrosomes could be due to a loss of key components, whereas multiple centrosomes could provide an imbalance of these components or simply lead to improper spindle alignment, unequal partition of chromosomal DNA and a DNA damage response [37,40,50]. Alteration of centrosomal components that results in inhibition of cytokinesis and centrosome duplication has been shown to induce cell cycle arrest [74,75,100]. Both loss and overexpression of centriolin, a newly identified centrosomal component, induces cytokinetic defects and a G 1 -phase cell cycle arrest [100].…”

Section: Discussionmentioning

confidence: 99%

“…Centrin, a 20kDa protein required for centrosome duplication, is rapidly localized to the distal lumen of developing centrioles and stably maintained in the lumen of the developed daughter centriole (DC) and MC [39,62,75]. Because centrin is integral to each centriole of a centrosomal pair, it is often used as a cytological marker for centrosomal maturity and for determining the cell cycle stage based on the number and position of the centrioles.…”

Section: Expression Of Akap450 C-terminal Pact Domain Dissociates Endmentioning

confidence: 99%

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Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

Don

Dallapiazza

Bennin

et al. 2006

Experimental Cell Research

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Cyclin G2 is an atypical cyclin that associates with active protein phosphatase 2A. Cyclin G2 gene expression correlates with cell cycle inhibition; it is significantly upregulated in response to DNA damage and diverse growth inhibitory stimuli, but repressed by mitogenic signals. Ectopic expression of cyclin G2 promotes cell cycle arrest, cyclin dependent kinase 2 inhibition, and the formation of aberrant nuclei [1]. Here we report that endogenous cyclin G2 copurifies with centrosomes and microtubules (MT), and that ectopic G2 expression alters microtubule stability. We find exogenous and endogenous cyclin G2 present at microtubule organizing centers (MTOCs) where it colocalizes with centrosomal markers in a variety of cell lines. We previously reported that cyclin G2 forms complexes with active protein phosphatase 2A (PP2A) and colocalizes with PP2A in a detergent resistant compartment. We now show that cyclin G2 and PP2A colocalize at MTOCs in transfected cells, and that the endogenous proteins copurify with isolated centrosomes. Displacement of the endogenous centrosomal scaffolding protein AKAP450 that anchors PP2A at the centrosome, resulted in the depletion of centrosomal cyclin G2. We find that ectopic expression of cyclin G2 induces microtubule bundling and resistance to depolymerization, inhibition of polymer regrowth from MTOCs, and a p53 dependent cell cycle arrest. Furthermore, we determined that a 100 amino acid carboxy-terminal region of cyclin G2 is sufficient to both direct GFP localization to centrosomes and induce cell cycle inhibition. Colocalization of endogenous cyclin G2 with only one of two GFPcentrin tagged centrioles, the mature centriole present at microtubule foci, indicate that cyclin G2 resides primarily on the mother centriole. Copurification of cyclin G2 and PP2A subunits with microtubules and centrosomes, together with the effects of ectopic cyclin G2 on cell cycle progression, nuclear morphology, and microtubule growth and stability, suggests that cyclin G2 may modulate the cell cycle and cellular division processes through modulation of PP2A and centrosomal associated activities.

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Section: Discussionmentioning

confidence: 99%

Section: Expression Of Akap450 C-terminal Pact Domain Dissociates Endmentioning

confidence: 99%

Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

Don

Dallapiazza

Bennin

et al. 2006

Experimental Cell Research

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“…Multipolar spindles can result from deregulated centrosome duplication followed by MT nucleation at ectopic centrosomes (Hinchcliffe and Sluder, 2001;Khodjakov and Rieder, 1999). Thus, we surveyed the status of ␥-tubulin (marks the ring structure that nucleates spindle MT assembly; Moudjou et al, 1996) and centrin-2 (a component of the centriole that regulates centriolar duplication; Salisbury et al, 2002). The data consistently reported multiple ␥-tubulin foci in cells with multipolar spindles.…”

Section: Hsac1 and Organization Of The Mitotic Spindlementioning

confidence: 97%

The Sac1 Phosphoinositide Phosphatase Regulates Golgi Membrane Morphology and Mitotic Spindle Organization in Mammals

Liu

Boukhelifa

Tribble

et al. 2008

MBoC

131

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Phosphoinositides (PIPs) are ubiquitous regulators of signal transduction events in eukaryotic cells. PIPs are degraded by various enzymes, including PIP phosphatases. The integral membrane Sac1 phosphatases represent a major class of such enzymes. The central role of lipid phosphatases in regulating PIP homeostasis notwithstanding, the biological functions of Sac1-phosphatases remain poorly characterized. Herein, we demonstrate that functional ablation of the single murine Sac1 results in preimplantation lethality in the mouse and that Sac1 insufficiencies result in disorganization of mammalian Golgi membranes and mitotic defects characterized by multiple mechanically active spindles. Complementation experiments demonstrate mutant mammalian Sac1 proteins individually defective in either phosphoinositide phosphatase activity, or in recycling of the enzyme from the Golgi system back to the endoplasmic reticulum, are nonfunctional proteins in vivo. The data indicate Sac1 executes an essential household function in mammals that involves organization of both Golgi membranes and mitotic spindles and that both enzymatic activity and endoplasmic reticulum localization are important Sac1 functional properties. INTRODUCTIONSpatial and temporal regulation of intracellular signaling in eukaryotic cells involves the compartmentalization of membrane surfaces into discrete, albeit often transient, functional units. There are several biochemical strategies by which cells generate such units or domains. One well-established strategy uses the chemical diversity offered by phosphoinositides (PIPs), i.e., phosphorylated forms of phosphatidylinositol (PtdIns) (Majerus, 1997;Fruman et al., 1998;Strahl and Thorner, 2007). The chemical heterogeneity of individual PIP species permits the construction of chemically unique platforms on membrane surfaces that, in turn, recruit unique cohorts of proteins that drive specific biological reactions. Spatial and temporal control of such reactions requires a finely coordinated balance between the activities of the lipid kinases that produce PIPs and the activities of enzymes that degrade them. PIP turnover is catalyzed by two general classes of enzymes: phospholipases and PIP phosphatases.Although experimental scrutiny of the phospholipases has historically been more intense, recent demonstrations of the significant biological functions played by PTEN, the myotubularins, and synaptojanins highlight the general importance of PIP phosphatases (Wishart et al., 2001;Wishart and Dixon, 2002;Wenk and De Camilli, 2004).The SAC domain derives from the yeast Sac1 protein (ySac1; Cleves et al., 1989), and it represents a signature for PIP phosphatase catalytic activity . PIP phosphatases such as phosphatase and tensin homolog (mutated in multiple advanced cancers 1) (PTEN) (Maehama et al., 2001), synaptojanins (Cremona et al., 1999), and synaptojanin-like proteins (Srinivasan et al., 1997;Stolz et al., 1998) all harbor SAC domains. The prototypical member of this family, ySac1, catalyzes the dephosphoryla...

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“…The staining of cells for g-tubulin was used as a marker for centrosomes, whereas the centrioles within the centrosome were visualized using Centrin-2 antibodies (Stearns et al 1991;Salisbury et al 2002). The pair of centrioles within the centrosome is surrounded by an amorphous, proteinaceous material called the pericentriolar material (PCM), and an antibody directed to pericentrin protein was used as marker for the PCM (Doxsey et al 1994).…”

Section: Immunofluorescence Immunoprecipitation and Antibodiesmentioning

confidence: 99%

Meier-Gorlin syndrome mutations disrupt an Orc1 CDK inhibitory domain and cause centrosome reduplication

Hossain

Stillman

2012

Genes Dev.

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Like DNA replication, centrosomes are licensed to duplicate once per cell division cycle to ensure genetic stability. In addition to regulating DNA replication, the Orc1 subunit of the human origin recognition complex controls centriole and centrosome copy number. Here we report that Orc1 harbors a PACT centrosome-targeting domain and a separate domain that differentially inhibits the protein kinase activities of Cyclin E–CDK2 and Cyclin A–CDK2. A cyclin-binding motif (Cy motif) is required for Orc1 to bind Cyclin A and inhibit Cyclin A–CDK2 kinase activity but has no effect on Cyclin E–CDK2 kinase activity. In contrast, Orc1 inhibition of Cyclin E–CDK2 kinase activity occurs by a different mechanism that is affected by Orc1 mutations identified in Meier-Gorlin syndrome patients. The cyclin/CDK2 kinase inhibitory domain of Orc1, when tethered to the PACT domain, localizes to centrosomes and blocks centrosome reduplication. Meier-Gorlin syndrome mutations that disrupt Cyclin E–CDK2 kinase inhibition also allow centrosome reduplication. Thus, Orc1 contains distinct domains that control centrosome copy number and DNA replication. We suggest that the Orc1 mutations present in some Meier-Gorlin syndrome patients contribute to the pronounced microcephaly and dwarfism observed in these individuals by altering centrosome duplication in addition to DNA replication defects.

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Centrin-2 Is Required for Centriole Duplication in Mammalian Cells

Abstract: These results demonstrate a requirement for centrin in centriole duplication and demonstrate that centrioles play a role in organizing spindle pole morphology and in the completion of cytokinesis.

Cited by 284 publications

References 46 publications

Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

Cyclin G2 is a centrosome-associated nucleocytoplasmic shuttling protein that influences microtubule stability and induces a p53-dependent cell cycle arrest

The Sac1 Phosphoinositide Phosphatase Regulates Golgi Membrane Morphology and Mitotic Spindle Organization in Mammals

Meier-Gorlin syndrome mutations disrupt an Orc1 CDK inhibitory domain and cause centrosome reduplication

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