细胞科学 el science (13 蔡国平
细胞科学 Cell Science （10.3） 蔡国平
10.3 The structure and composition of microtubules (MTS) MTS are hollow, cylindrical structures that occur in nearly every eukaryotic cell that has been scrutinized with EM. MTs have an outer diameter of 24- 25nm. a wall thickness of approximately 5 nm, and lengths that may extend across the length or breadth of a cell 1 Tubulin Globular tubulin subunits are arranged in 13 X longitudinal rows, termed protofilaments, that are aligned parallel to the long axis of the tubule There are three isoforms of tubulins: a, B, y tubulin, MT consists of a, B tubulin; y tubulin is held in MTOC to bind a B tubulin dimers
10.3 The structure and composition of microtubules (MTs) MTs are hollow, cylindrical structures that occur in nearly every eukaryotic cell that has been scrutinized with EM. MTs have an outer diameter of 24~25nm, a wall thickness of approximately 5 nm, and lengths that may extend across the length or breadth of a cell. 1.Tubulin Globular tubulin subunits are arranged in 13 x longitudinal rows, termed protofilaments, that are aligned parallel to the long axis of the tubule. There are three isoforms of tubulins: tubulin, MT consists of tubulin; tubulin is held in MTOC to bind tubulin dimers
15u Figure 9.12 Localization of microtubules of a large, flat, cultured mouse cell is revealed by fluorescent anti-tubulin antibodies Microtubules are seen to extend from the peri
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tubulin lumen protofilament end minus end microtubule (B)
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a-Tubulin B-Tubulin GTP Taxotere Subunit a-Tubulin GTP GDP B-Tubuli 8 n Protofilament 24 nm A FIGURE 19-2 Microtubule structure (a) Ribbon diagram of
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