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The cell and tissues
Published in Peate Ian, Dutton Helen, Acute Nursing Care, 2020
The centrosome is an area near the nucleus that contains a pair of rod-like structures called the centrioles. This area and the centrioles are associated with the process of cell division. They produce the mitotic spindle in dividing cells. The centrioles also form the basis of cilia and flagella. Cilia are typically found on the columnar epithelium of the lining of the respiratory tract. They are involved in the movement of dust particles and mucus up the respiratory tract. The only example found in humans of a cell with a flagellum is the sperm.
General Radiation Cytopathology
Published in George W. Casarett, Radiation Histopathology, 2019
Controversy over the relative importance of cytoplasmic versus nuclear effects, or their order in sequence of mechanisms, is still not completely resolved. Abnormalities of division have been considered due largely to effects on chromatin or chromosomes. However it is conceivable that some of the abnormalities could represent alterations in cytoplasmic structures, such as centrosomes or centrioles, or in cytoplasmic membranes. Furthermore, there are studies which suggest the presence of a chromosome breakage factor in cell-free plasma of irradiated subjects. The identity of such a factor and its mechanism are still unknown, but such reports support the idea that indirect mechanisms may be responsible for some of the radiation-induced chromosomal effect.
Cell Biology
Published in C.S. Sureka, C. Armpilia, Radiation Biology for Medical Physicists, 2017
Centrosomes (shown in the Figure 1.1) are composed of two centrioles (cylindrical structures located near the nucleus) and can produce microtubules (key component of the cytoskeleton) of a cell. During cell division, the pair of centrioles detach from each other. During this process, thin cytoplasmic spindle fibers are formed between the centrioles. These spindle fibers are connected to the specific chromosome in order to distribute the number of chromosomes between two daughter cells equally.
Interactive effects of AURKA polymorphisms with smoking on the susceptibility of oral cancer
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Chao Huang, Lili Wang, Hongguang Song, Cungang Wu
Relationship between centrosome abnormity and malignant tumours has got widespread attention since the beginning of the 20th century [15]. The function of centrosome ensuring the symmetry and dual polarity of cell division is a necessary condition for the right separation of chromosomes [16]. It has been verified that centrosome dysfunction can lead to the abnormal chromosome separation in malignant tumours [17]. Centrosomes number in almost all human solid tumours is abnormal. AURKA is a kind of functional kinase of the centrosome, and as an oncogene [18], the amplification and over-expression of AURKA gene have been detected in variety of human tumours [19]. AURKA polymorphisms have been proved by many studies to be the genetic factors of disrupting the centrosome functions [20]. Results of previous studies are different and this may be due to different races, tumours and sample sizes of the studies [21,22].
Retinal dystrophy associated with a Kizuna (KIZ) mutation and a predominantly macular phenotype
Published in Ophthalmic Genetics, 2019
Yue Zhao, Razek Georges Coussa, Meghan J. M. DeBenedictis, Elias I. Traboulsi
Kizuna (KIZ) is a 673 amino acid protein encoded by 12kb on chromosome 20p11.23 and is involved in ciliary structural integrity. Studies in HeLA cell lines have demonstrated its role in maintaining centrosome stability during prometaphase (2). During mitosis, mature centrosomes, consisting of a pair of centrioles surrounded by pericentriolar material, form at each pole of the dividing cell. From the pericentriolar material, microtubules are successively enucleated to form spindle complexes that attach to the centrally aligned chromosomes and form scaffolding for chromatid separation (9,10). Oshimori et al. showed that phosphorylation of Kiz Thr-379 is required for centrosomal maturation and chromosomal movement (2). In the absence of Kiz, dissociation of pericentriolar material from the centrosome results in spindle fragmentation (1). In mice, Kizuna has been shown to be preferentially expressed in the retina, especially in the outer nuclear layer (1). It is hypothesized that the outer retina is predominantly affected by KIZ mutations. In the present case, KIZ c.226 C > T (p.Arg76*) is a nonsense mutation that results in a truncated non-functional protein and hence is pathogenic in a homozygous state.
A novel CEP290 disease-causing variant identified in a patient with leber congenital amaurosis using a medical diagnostic panel sequencing
Published in Ophthalmic Genetics, 2022
Bin-Bin Chen, Yi Zhai, Ya-Nan Huo, Shuo Yang, Zhi-Yong Zhang
CEP290 protein is a centrosomal protein of 2479 amino acids with a molecular weight of 290 kDa. It was first identified in a proteomic analysis of the human centrosome. The protein is strongly conserved throughout evolution and contains several predicted motifs (15). The CEP290 protein is expressed in the centrosome of dividing cells, the nucleus, and the basal bodies of the primary cilia in many cell types, such as photoreceptor (16). Ultrastructural analysis has shown that the CEP290 protein resides at Y-link junctions of the ciliary transition zone and stabilizes the linkage of axoneme microtubules to the ciliary membrane (17).