D 2004

THE ROLE OF CALMODULIN IN KARYOKINESIS AND IN CYTOKINESIS.

HAVELKOVÁ, Marie

Basic information

Original name

THE ROLE OF CALMODULIN IN KARYOKINESIS AND IN CYTOKINESIS.

Name in Czech

FUNKCE KALMODULINU V KARYOKINEZI A CYTOKINESI.

Authors

HAVELKOVÁ, Marie (203 Czech Republic, guarantor)

Edition

2004. vyd. Slovensko, 32nd Intarnational Conference on yeasts. 2 pp. 2004

Publisher

SAS a CHÚSAS Bratislava, Slovensko

Other information

Language

English

Type of outcome

Stať ve sborníku

Field of Study

Genetics and molecular biology

Country of publisher

Slovakia

Confidentiality degree

není předmětem státního či obchodního tajemství

RIV identification code

RIV/00216224:14410/04:00025476

Organization unit

Faculty of Education

Keywords (in Czech)

kalmodulin, karyonineze, cytokineze, kvasinky, buněčný cyklus, cytoskelete, mutanty, nepřímá fluorescence

Keywords in English

calmodulin; karyokinesis; cytokinesis; yeasts; yeast cell cycle; cytoskeleton; mutants; indirect immunofluorescence

Tags

International impact, Reviewed
Změněno: 11/3/2010 17:27, doc. MUDr. Marie Havelková, CSc.

Abstract

V originále

Recently, the intracellular localization of protein calmodulin and cytoskeletal actin in cells of yeast strain Yarrowia lipolytica has been studied by indirect immunofluorescence using anti calmodulin antibody and rhodamine conjugated phalloidin. We have found that there exist relationships between cytoskeletal components and protein calmodulin. Microtubule disassembly is promoted by calmodulin in the presence of Ca2+. Calmodulin is also implicated in regulation of microfilaments. Distributions of calmodulin changes in a typical way during the cell cycle. In the unbudded cell calmodulin localizes to a sharp crescent shaped patch on the cortex of the cell. At bud emergence, calmodulin concentrates to the budding portion. All budded cells exhibit bright staining calmodulin dots at the tip of the bud. In small budded cells are staining dots localized at the bud neck, in cells with large buds calmodulin diffuses throughout the entire bud. At cytokinesis, calmodulin is mainly present at the connecting passage between the mother and daughter cells. Double staining experiments were carried out. They have shown that the location of calmodulin dots coincides with that of actin structures. Calmodulin emerges in mentioned parts of the cell always sooner than actin. This fact proved that calmodulin is required for distribution of actin dots. The finding that calmodulin is unconditionally needed for nuclear division was particularly important. Therefore we studied new, intentionally prepared mutants Y. lipolytica in our present experiments. We found that opened cell cycle without sufficient level of calmodulin stops in M-phase. Inhibition of karyokinesis start caused by the low level of calmodulin is reversible and without consequences, if the blockade takes less than four hours. After increase in calmodulin level, the karyokinesis starts in 15 minutes and it passes correctly. But if the blockade of karyokinesis takes more than four hours as a result of extremely low level of intracellular calmodulin, the cell reacts to calmodulin level normalization late (after 4 hours) and the process of the karyokinesis is very aberrant. However, the cytokinesis is not restored no more. After about 20 hours, we can observe cell formations vary in size in the culture with from two to four nuclei different in size and DNA content. In these cells calmodulin and actin dots are dispersed all over the periphery of cell and their number and size are strongly reduced.

In Czech

Funkce a význam kalmodulinu pro jaderné dělení a cytokinezi bylo sledováno na vybraných modelových objektech, mutantách buněčného cyklu Yarrowia lipolytica. Výsledky jsou předpokladem pro další experimentální práce - výběr vhodných cytostatik a kacerostatik.

Links

MSM 144100001, plan (intention)
Name: Učitelé a zdraví (Psychologický přístup)
Investor: Ministry of Education, Youth and Sports of the CR, Teachers and Health