Centrioles Research Articles

C-Cbl Acts as an E3 Ligase Against DDA3 for Spindle Dynamics and Centriole Duplication during Mitosis.

The spatiotemporal mitotic processes are controlled qualitatively by phosphorylation and qualitatively by ubiquitination. Although the SKP1-CUL1-F-box protein (SCF) complex and the anaphase-promoting complex/cyclosome (APC/C) mainly mediate ubiquitin-dependent proteolysis of mitotic regulators, the E3 ligase for a large portion of mitotic proteins has yet to be identified. Here, we report c-Cbl as an E3 ligase that degrades DDA3, a protein involved in spindle dynamics. Depletion of c-Cbl led to increased DDA3 protein levels, resulting in increased recruitment of Kif2a to the mitotic spindle, a concomitant reduction in spindle formation, and chromosome alignment defects. Furthermore, c-Cbl depletion induced centrosome over-duplication and centriole amplification. Therefore, we concluded that c-Cbl controls spindle dynamics and centriole duplication through its E3 ligase activity against DDA3.

The self-made beauty of the centriole

The self-made beauty of the centriole

Centriole Mediated Neurogenesis of OSN in Fish

Centriole Mediated Neurogenesis of OSN in Fish

Vanishing Centrioles in Meiosis.

Vanishing Centrioles in Meiosis.

How the newborn centriole becomes a mother

How the newborn centriole becomes a mother

Bioinformatics research of CD44 and epithelial cell adhesion molecule related genes and pathways in colorectal cancer

Objective To investigate genes and involved biological processes closely associated with stem cell markers of colorectal cancer-epithelial cell adhesion molecule (EpCAM)+ and CD44+. Methods By the bioinformatics method, with microarray data of colorectal cancer from gene expression omnibus (GEO) database and R2 platform, the genes significantly related with CD44 and EpCAM expression were screened out. The differences in expression of related genes were analyzed on the basis of gender, family history of cancer, alcohol and Dukes stage. The expression of related genes in colorectal cancer was compared with that of other tumors and healthy subjects. At same time, the pathways of the genes and Kyoto encyclopedia of genes and genomes (KEGG) of CD44 and EpCAM significantly related genes were analyzed with gene ontology (GO) and KEGG method. Single factor analysis of variance and Chi-square test of four-fold table with correction for continuity were used for statistical analysis by R2 platform embedded statistical tools. Results The expressions of CD44 and EpCAM were detected in all 315 colorectal cancer samples.A total of 888 and 6 316 genes were screened out which were significantly associated with CD44 and EpCAM expression. CD44 was positively correlated with EpCAM. There was no obvious correlation between the expression of five genes which expressed in all 315 tissues and gender family history of cancer, alcohol and Dukes stage (all P>0.05). By further compared with the expression in other tumors and tissues, the expressions of two genes solute carrier family 12, member 2 (SLC12A2) and proteome of centriole 1 centriolar protein B (POC1B) in colorectal tumor were significantly higher than that in other tumors (F=289.422、128.456, all P<0.01), and its expression in colorectal cancer was obviously higher than that in tissues of health subjects (F=349.519、128.456, all P<0.01). GO analysis indicated there were 15 GO semantics related with both CD44 and EpCAM. The genes related with CD44 and EpCAM were analyzed by KEGG access pathway method, while seven and 10 pathways were found to be statistically significant (all P<0.01). Conclusions CD44 and EpCAM commonly expressed in colorectal cancer. The genes related with CD44 and EpCAM expression are involved in multiple tumor biological processes. Key words: CD44; EpCAM; Colorectal neoplasms; Neoplastic stem cells; Bioinformatics; Gene microarray

STIL binding to the Polo-box 3 of PLK4 regulates centriole duplication - Backbone assignment of human Polo-box 3 bound to STIL

STIL binding to the Polo-box 3 of PLK4 regulates centriole duplication - Backbone assignment of human Polo-box 3 bound to STIL

Tracing the origins of centrioles, cilia, and flagella

Tracing the origins of centrioles, cilia, and flagella

Origin of the cilium: novel approaches to examine a centriolar evolution hypothesis

Abstract Recently, a new hypothesis was proposed regarding the evolution of the cilium from an enveloped RNA virus (Satir et al. , 2007, Cell Motil. Cytoskeleton 64 , 906). The hypothesis predicts that there may be specific centriolar or basal body RNAs with sequences reminiscent of retroviruses, and/or that the nuclear genes for certain centriole-specific proteins would have viral origins. Four independent laboratories have reported the existence of centrosomal RNA (cnRNA). Methods for studying cnRNA are described. We analyzed evidence of relatedness of known full-length cnRNAs to extant viral molecules. Out of 14 cnRNAs studied, 12 have similarity to entries in viral databases, all but one of these with E-values of ≤1e −4 . Some centrosomal, and possibly uniquely centriolar, proteins also have relatives in viral databases that meet the criteria accepted to indicate a relationship by descent. Nine general cytoskeleton proteins exhibited no significant similarity to viral proteins. The speculation that centrioles are invaders of RNA viral origin in the evolving eukaryotic cell is strengthened by these findings.

Staining the centrioles with Feulgen and Giemsa.

Staining the centrioles with Feulgen and Giemsa.

Polypolar spindle formation during first cell cycle in rainbow trout Oncorhynchus mykiss embryos after heat-shock treatment

Heat shock has been used to inhibit cleavage for the induction of monogenic diploids or tetraploid in animals, but usually the success rate is low. Heat-shocked rainbow trout Oncorhynchus mykiss embryos were used in this histological study to clarify the causes of this low success rate. Embyros treated with hydrostatic pressure were used for comparison. After heat shock had disorganized the spindles, polypolar (tripolar or tetrapolar) spindles in addition to bipolar spindles were often reassembled soon after treatment. The embryos then completed tripolar or tetrapolar division at the first mitosis, and directly turned into three- or four-cell embryos as a result of the first cleavage. During the second mitosis, a monopolar spindle was formed in each blastomere of four-cell embryos and approximately 60% of three-cell embryos. In the remaining three-cell embryos, two of the three blastomeres formed a monopolar spindle, and the third one formed a bipolar spindle. The formation of polypoles is assumed to be caused by insufficient disorganization of daughter centrioles and splitting from the mother centriole by heat shock. Polypolar division is considered to be the cause of aneuploidy and the low success rate of chromosome set doubling. In the case of hydrostatic pressure treatment, the regenerated spindles were bipolar in almost all embryos.

Building centrioles

Building centrioles

Ultrastructure of spermatozoa of rats (Rattus norvegicus). Use of 3 technics in transmission electron microscopy

Ultrastructures spermatozoa taken from the seminiferous tubules of rat testes (Rattus norvegicus) were observed under transmission electron microscopy, using the techniques of ultrathin sections, microspreading specimens and replicas. The heads of isolated spermatozoa were of homogeneously high electron density, and had a slightly curved end; in longitudinal sections these zones were composed of a compact homogeneous DNA, covered by a nuclear envelop, cell membrane and small amounts of acrosomal material. The middle piece contained the modified centrioles in the junction zone and flagella microtubules. In transverse sections as well as in replicas, this region consisted of 10 pairs of microtubules and 9 dense fibers surrounded circularly by the mitochondria (mitochondrial sheath).

Are Centrioles Semiautonomous?

Are Centrioles Semiautonomous?

Roles for centrioles

The Centriole: A Central Enigma of Cell Biology. By D.N. Wheatley. Pp.232. ISBN 0-444-80359-9. (Elsevier/North-Holland Biomedical: 1982.) Dfl.190, $88.50.

Centrioles and Mitosis in Some Oömycetes

Centrioles and Mitosis in Some Oömycetes

Centrioles and Mitosis in Some Oomycetes

Centrioles and Mitosis in Some Oomycetes

Centrioles in Sorosphaera

Centrioles in Sorosphaera

Centrioles in Sorosphaera

4. -. 1973. Studies on Emmonsiella capsulata I. Heterothallism and development of the ascocarp. Mycologia 65: 109-121. 5. McDonough, E. S., and Ann L. Lewis. 1968. The ascigerous stage of Blastomyces derwatitidis. Mycologia 60: 76-83. 6. Reynolds, E. S. 1963. The use of lead citrate at high pH as an electronopaque stain in electron microscopy. J. Cell Biol. 19: 208-212. 7. Ryter, A., and E. Kellenberger. 1958. Rtude au microscope electronique de plasmas contenant de l'acide deoxyribonucleique. I. Les nucleoides des bacteries en croissance active. Z. Naturforsch. 136: 597-605. 8. Sabatini, D. C., K. Bensch, and R. J. Barnett. 1963. Cytochemistry and electron microscopy: The preservation of cellular ultrastructure and enzymatic activity by aldehyde fixation. J. Cell Biol. 17: 19-58.

Centrioles in hepatocytes.

In der normalen und regenerierenden Rattenleber wurden Zentriolen gefunden. In der normalen Leberparenchymzelle erscheinen sie wahrscheinlich als Diplosomen. Haufig werden mehr als 2 Zentriolen in der einzelnen Leberparenchymzelle beobachtet, jedoch gibt es keine Anhaltspunkte fur eine zentriolare Replikation in den normalen Leberparenchymzellen. Teilhepatektomie tritt kurz nach Bildung von Tochterzentriolen auf. Das Vorkommen von Zilien scheint mit den Zentriolen der Leberparenchymzellen nicht verbunden zu sein.