Actin is a multi-functional protein that is involved in numerous cellular processes including cytoskeleton regulation, cell migration, and cellular integrity. In these processes, actin's role in respect to its structure, complex mechanical, and protein-binding properties has been studied primarily in the cytoplasmic and cellular membrane compartments. However, its role in somatic cell nuclei has recently become evident where it participates in transcription, chromatin remodeling, and DNA damage repair. What remains enigmatic is the involvement of nuclear actin in physiological processes that lead to the generation of germ cells, in general, and primary spermatocytes, in particular. Here, we will discuss the possible role and nuclear localization of actin during meiotic prophase I and its interaction with chromatin remodeling complexes, the latter being essential for the control of pairing of homologous chromosomes, cross-over formation, and recombination. It is our hope that this perspective article will extend the scope of actin's nuclear function in germ cells undergoing meiotic division.
- Klíčová slova
- actin, chromatin remodeling, nucleoskeleton, prophase I, spermatoproteasome,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Protoplast cultures are remarkable examples of plant cell dedifferentiation. The state of dedifferentiation is evidenced by changes in cell morphology, genome organization, as well as by the capability of protoplasts to differentiate into multiple types of cells (depending on the type of the stimulus applied). The first change in the genome structure is connected with large-scale chromatin decondensation, affecting chromocentres involving various types of these repetitive sequences. This paper describes not only the de- and recondensation of satellite DNA type I and 5S rDNA repetitive sequences, but it also compares the recondensation level of chromatin with the levels of oxidative stress which were decreased by using an antioxidant, as well as the capabilities of the antioxidative systems within protoplasts, during the first 72 h of their culture. It is demonstrated that the treatment of protoplasts with ascorbic acid not only decreased the level of oxidative stress but also positively stimulated the expression of the ascorbate peroxidase and catalase. It also led to a greater recondensation of the chromatin (when compared to the untreated protoplasts); in addition, it supported cell proliferation. It is concluded that large-scale genome relaxation is more directly connected with oxidative stress than with large changes in the expression of genes; and further, that its recondensation is related to the start of (as well as the level of) protection by the antioxidative systems.
- MeSH
- askorbátperoxidasa MeSH
- buněčné jádro enzymologie genetika metabolismus MeSH
- Cucumis sativus enzymologie genetika metabolismus MeSH
- katalasa genetika metabolismus MeSH
- mikrosatelitní repetice * MeSH
- oxidační stres * MeSH
- peroxidasy genetika metabolismus MeSH
- protoplasty enzymologie metabolismus MeSH
- rostlinné proteiny genetika metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- askorbátperoxidasa MeSH
- katalasa MeSH
- peroxidasy MeSH
- rostlinné proteiny MeSH
