Nucleosomes are composed of "histones" class of molecules.
<u>Explanation:</u>
Histones usually presented in eukaryotic nuclei of cells which seemed as strong level of proteins that bundle and organize DNA into structural groups called nucleosomes in biological science.
They are chromatin's chief protein elements, functioning as spools along which DNA spins, and playing a major role in regulating genes. Five forms of histones have been recognized:
- H1 (or H5), H2A, H2B, H3, and H4;
- H2A, H2B, H3, and H4 are the main histones and H1 and H5 are the linker histones.
Smooth muscle cells are found in the walls of hollow organs
It varies but mostly 32-34
Explanation:
Almost all eukaryotic proteins are subject to post-translational modifications during mitosis and cell cycle, and in particular, reversible phosphorylation being a key event. The recent use of high-throughput experimental analyses has revealed that more than 70% of all eukaryotic proteins are regulated by phosphorylation; however, the mechanism of dephosphorylation, counteracting phosphorylation, is relatively unknown. Recent discoveries have shown that many of the protein phosphatases are involved in the temporal and spatial control of mitotic events, such as mitotic entry, mitotic spindle assembly, chromosome architecture changes and cohesion, and mitotic exit. This implies that certain phosphatases are tightly regulated for timely dephosphorylation of key mitotic phosphoproteins and are essential for the control of various mitotic processes. This review describes the physiological and pathological roles of mitotic phosphatases, as well as the versatile role of various protein phosphatases in several mitotic events.
