Domain-specific changes of ciliary striated rootlets during the cell cycle in the hypotrich ciliate Paraurostyla weissei

1990 ◽  
Vol 96 (4) ◽  
pp. 617-630
Author(s):  
MARIA JERKA-DZIADOSZ
Keyword(s):  
Cell Cycle ◽  
Basal Body ◽  
Polyclonal Antibody ◽  
Paramecium Tetraurelia ◽  
Site Specific ◽  
Domain Specific ◽  
Interphase Cells ◽  
Cr System ◽  
The Right ◽  
In Cells

The dynamics of striated ciliary rootlets (cr) during development of ciliary structures in cells of the hypotrich ciliate Paraurostyla weissei was studied by immunostaining with polyclonal antibody raised against isolated cr of Paramecium tetraurelia. Wildtype cells and two mutants: mlm/pl showing multiple left marginal cirri and mlm/pl showing in addition a certain degree of pattern lability were used to study the boundaries of particular cortex domains. In interphase cells, cr are attached to all left marginal and caudal cirri and to only the posterior third of the right marginal cirri, cr appear in all nonoral primordia during the first wave of basal body proliferation. After nucleation and early elongation of cr, some cr undergo site-specific regression or stabilization. The spatial deployment of these different modes of development corresponds to specific cortical domains. In mlm/pl mutants, where specific cortical domains are broadened, changes in the cr system are characteristic for a given domain, regardless of its broadening, but boundaries between adjacent domains are weakened.

scholarly journals Changes in the distribution of a major fibroblast protein, fibronectin, during mitosis and interphase

1977 ◽  
Vol 74 (2) ◽  
pp. 453-467 ◽  
Author(s):  
S Stenman ◽  
J Wartiovaara ◽  
A Vaheri
Keyword(s):  
Electron Microscopy ◽  
Cell Cycle ◽  
Growth Control ◽  
Structural Role ◽  
Fibrillar Material ◽  
Interphase Cells ◽  
Dividing Cells ◽  
Mitotic Cells ◽  
In Cells

The distribution of a major fibroblast protein, fibronectin, was studied by immunofluorescence and immunoscanning electron microscopy in cultures of human and chicken fibroblasts during different phases of the cell cycle. The main findings were: (a) In interphase cells, the intensity of surface-associated fibronectin fluorescence correlated with that of intracellular fibronectin fluorescence. (b) The intensity of the fluorescence of both surface-associated and intracellular fibronectins was not changed in cells that were synthesizing DNA. (c) Mitotic cells had reduced amounts of surface-associated but not of intracellular fibronectin. The surface fibronectin that remained on meta-, ana-, or telophase cells had a distinct punctate distribution and was also localized to strands attaching the cells to the substratum. Fibronectin strands first reappeared on the surface of flattening cytoplasmic parts of telophase cells. (d) Fibronectin was also detected in extracellular fibrillar material on the growth substratum, particularly around dividing cells. Thus, surface-associated fibrillar fibronectin was present during G(1), S, and G(2) but in cells undergoing mitosis the distribution was altered and the amount appeared to be reduced. The observations on the distribution of surface-associated fibronectin suggest that rather than being involved in growth control this fibronectin plays a structural role in interactions of cells with the environment.

scholarly journals Sas-4 proteins are required during basal body duplication in Paramecium

2011 ◽  
Vol 22 (7) ◽  
pp. 1035-1044 ◽  
Author(s):  
Delphine Gogendeau ◽  
Ilse Hurbain ◽  
Graca Raposo ◽  
Jean Cohen ◽  
France Koll ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Basal Body ◽  
Basal Bodies ◽  
Paramecium Tetraurelia ◽  
Animal Cells ◽  
Centriole Duplication ◽  
Specific Order ◽  
In Cells

Centrioles and basal bodies are structurally related organelles composed of nine microtubule (MT) triplets. Studies performed in Caenorhabditis elegans embryos have shown that centriole duplication takes place in sequential way, in which different proteins are recruited in a specific order to assemble a procentriole. ZYG-1 initiates centriole duplication by triggering the recruitment of a complex of SAS-5 and SAS-6, which then recruits the final player, SAS-4, to allow the incorporation of MT singlets. It is thought that a similar mechanism (that also involves additional proteins) is present in other animal cells, but it remains to be investigated whether the same players and their ascribed functions are conserved during basal body duplication in cells that exclusively contain basal bodies. To investigate this question, we have used the multiciliated protist Paramecium tetraurelia. Here we show that in the absence of PtSas4, two types of defects in basal body duplication can be identified. In the majority of cases, the germinative disk and cartwheel, the first structures assembled during duplication, are not detected. In addition, if daughter basal bodies were formed, they invariably had defects in MT recruitment. Our results suggest that PtSas4 has a broader function than its animal orthologues.

The formation of basal body domains in the membrane skeleton of Tetrahymena

Development ◽  
1990 ◽  
Vol 109 (4) ◽  
pp. 935-942 ◽  
Author(s):  
N.E. Williams ◽  
J.E. Honts ◽  
J. Kaczanowska
Keyword(s):  
Cell Cycle ◽  
Basal Body ◽  
Membrane Skeleton ◽  
Basal Bodies ◽  
Molecular Events ◽  
Similarities And Differences ◽  
The Individual ◽  
In Cells

Differentiated regions within the membrane skeleton are described around basal bodies in the ciliary rows of Tetrahymena. These domains, approximately 1 micron in diameter, are characterized by a relatively dense ultrastructure, the presence of a family of proteins called K antigens (Mr 39–44 × 10(3)) that are recognized by mAb 424A8, and the apparent exclusion of major membrane skeleton proteins that are present in most other regions of the cell (Mr 135, 125 × 10(3]. Mature basal body domains are asymmetric, reflecting the polarity of the cell as a whole. A similar differentiation of the membrane skeleton occurs in the oral apparatus, except here the K antigens surround four clusters of basal bodies (from which this cell takes its name) rather than the individual basal bodies. The development of new basal body domains in the cell cycle is described, with similarities and differences noted between somatic and oral regions of the cell. It is concluded that the capacity of this cell for precise topographic regulation of molecular events in the membrane skeleton makes it a useful model for the study of cortical differentiation in cells generally.

scholarly journals Centrin Gene Disruption Impairs Stage-specific Basal Body Duplication and Cell Cycle Progression inLeishmania

2004 ◽  
Vol 279 (24) ◽  
pp. 25703-25710 ◽  
Author(s):  
Angamuthu Selvapandiyan ◽  
Alain Debrabant ◽  
Robert Duncan ◽  
Jacqueline Muller ◽  
Poonam Salotra ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Basal Body ◽  
Gene Disruption ◽  
Cell Cycle Progression ◽  
Cycle Progression

scholarly journals DNA tumor virus oncoproteins and retinoblastoma gene mutations share the ability to relieve the cell's requirement for cyclin D1 function in G1.

1994 ◽  
Vol 125 (3) ◽  
pp. 625-638 ◽  
Author(s):  
J Lukas ◽  
H Müller ◽  
J Bartkova ◽  
D Spitkovsky ◽  
A A Kjerulff ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Complex Formation ◽  
Cyclin D1 ◽  
Cell Lines ◽  
T Antigen ◽  
Regulatory Function ◽  
Retinoblastoma Gene ◽  
Checkpoint Control ◽  
Wild Type ◽  
In Cells

The retinoblastoma gene product (pRB) participates in the regulation of the cell division cycle through complex formation with numerous cellular regulatory proteins including the potentially oncogenic cyclin D1. Extending the current view of the emerging functional interplay between pRB and D-type cyclins, we now report that cyclin D1 expression is positively regulated by pRB. Cyclin D1 mRNA and protein is specifically downregulated in cells expressing SV40 large T antigen, adenovirus E1A, and papillomavirus E7/E6 oncogene products and this effect requires intact RB-binding, CR2 domain of E1A. Exceptionally low expression of cyclin D1 is also seen in genetically RB-deficient cell lines, in which ectopically expressed wild-type pRB results in specific induction of this G1 cyclin. At the functional level, antibody-mediated cyclin D1 knockout experiments demonstrate that the cyclin D1 protein, normally required for G1 progression, is dispensable for passage through the cell cycle in cell lines whose pRB is inactivated through complex formation with T antigen, E1A, or E7 oncoproteins as well as in cells which have suffered loss-of-function mutations of the RB gene. The requirement for cyclin D1 function is not regained upon experimental elevation of cyclin D1 expression in cells with mutant RB, while reintroduction of wild-type RB into RB-deficient cells leads to restoration of the cyclin D1 checkpoint. These results strongly suggest that pRB serves as a major target of cyclin D1 whose cell cycle regulatory function becomes dispensable in cells lacking functional RB. Based on available data including this study, we propose a model for an autoregulatory feedback loop mechanism that regulates both the expression of the cyclin D1 gene and the activity of pRB, thereby contributing to a G1 phase checkpoint control in cycling mammalian cells.

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