北京大学:《细胞生物学 Cell Science》课程教学资源(PPT课件讲稿)Structure and composition of microfilament(蔡国平)

细胞科学 Science 蔡国
细胞科学 Cell Science (10.2) 蔡国平

10.2 Structure and composition of microfilament They are solid, thinner filament structures(6-8 nm, in diameter) composed of a double-helical polymer of the protein actin. And microfilaments play a key role of in virtually all types of contractility and location of cells as well as motility within cells L. Actin The most abundant protein in many eukaryocytic cells of constituting 5 or more of the total cell proteins(20% of their mass is actin in muscle cell). A typical cytosolic concentration of actin in nonmuscle cells is 0. 5mM Actin has MW 42KD with x 375 amino acid residues encoded by a large, highly conserved gene family. Some single-celled enkaryotes, e.g. yeasts and amebas have only a single actin gene, whereas many eukaryotes contain multple actin genes
10.2 Structure and composition of microfilament They are solid, thinner filament structures (6-8 nm, in diameter) composed of a double-helical polymer of the protein actin. And microfilaments play a key role of in virtually all types of contractility and location of cells as well as motility within cells. 1. Actin The most abundant protein in many eukaryocytic cells, of constituting 5 % or more of the total cell proteins (20% of their mass is actin in muscle cell). A typical cytosolic concentration of actin in nonmuscle cells is 0.5mM. Actin has MW 42KD with ~ 375 amino acid residues, encoded by a large, highly conserved gene family. Some single-celled enkaryotes, e.g. yeasts and amebas have only a single actin gene, whereas many eukaryotes contain multple actin genes

In vertebrate, there are three isoforms, a,B, y actin, together form a closely related family whose members are specialised for different types of motile processes. The structure of actin has been remarkably conserved throughout the couse of evolution (it is 88% identical between yeast/ rabbit muscle). The four a-actin isoforms present in varios muscle cells and the B-and y-actin isoform present in nonmuscle cells differ at only 4 to 5 positions. The a-actin is associated with contractile structure, B-actin is at the front of the cell, forming filaments. Actin filaments consist of one or two isoforms in skeletal cells. consist of a-actin. while in smooth muscle cell consist of a-actin and y-actin; in nonmuscle cells, consist of the B-and y-actin
In vertebrate, there are three isoforms, actin, together form a closely related family whose members are specialised for different types of motile processes. The structure of actin has been remarkably conserved throughout the couse of evolution (it is 88% identical between yeast/ rabbit muscle). The four -actin isoforms present in varios muscle cells and the - and -actin isoform present in nonmuscle cells differ at only 4 to 5 positions. The -actin is associated with contractile structure; -actin is at the front of the cell, forming filaments. Actin filaments consist of one or two isoforms, in skeletal cells, consist of -actin, while in smooth muscle cell consist of -actin and -actin; in nonmuscle cells, consist of the - and -actin


Figure 22-15 The Molecular Structure of G-Actin Monomer X-ray crystallography shows that the G-actin monomer is shaped somewhat like a U A nucleotide (ATP or ADP) binds reversibly in a groove in the protein. When G-actin monomers polymerize into F-actin, the mouth of the groove is covered by another G-actin monomer, trapping the bound nucleotide inside. In addition, binding of one G-actin to another forces the mouth of the groove to close more tightly on the bound nucleotide, promoting hydrolysis of the ATP

Fis gure 11.2 Assembly and structure of actin fila ments (A)Actin monomers(G actin) polymerize to form actin filaments (F actin). The first slep is the formation of dimers and trimers, which then grow by the addition of monomers to both ends.(B)Structure of an actin monomer(C")Space-filling model of F actin. Nine actin monomers an rpr nted in different colors. (O Dan Richardson

actin molecule Figure 16-25 Actin filaments. (A) Electron micrographs of negatively stained actin fil minus end minus end aments. (B)Arrangement of actin mole cules in an actin filament, Each filament may be thought of as a two-stranded helix with a twist repeating every 37 nm. Strong interactions between the two strands pre vent the strands from separating, (C)The identical subunits of an actin filament are depicted in different colors to emphasize the close interaction between each actin molecule and its four nearest neighbors (A, courtesy of Roger Craig: C, from K.C. Holmes et al. Nature 347: 44-49, 1990, copyright Macmillan Magazines Ltd 37 nm plus end 50 nm

ntive neuro- Gehrig dis- skeletal ab- the disease en found to gesting that he of several ingestion that marily in tis- activities that bly and inter- The neural developing tire width of ts as the tilage of the od cells pa r debris and Figure 9.48 Determining the loc

a binding cleft N-terminus C-terminus

Act a-Actinin Zonal Actin Cytokeratins In ICoM erminal Fimbrin TW260240 F1.3.5
按次数下载不扣除下载券;
注册用户24小时内重复下载只扣除一次;
顺序:VIP每日次数-->可用次数-->下载券;
- 《植物生理学》课程PPT教学课件(双语版)第三章 植物的无机营养(3-1)植物的水分代谢.ppt
- 《植物生理学》课程PPT教学课件(双语版)Part 3 Plant Mineral Nutrition.ppt
- 《植物生理学》课程PPT教学课件(双语版)Part 2 Long-Distance Transport.ppt
- 《植物生理学》课程PPT教学课件(双语版)Part 1 Photosynthesis.ppt
- 《植物生理学》课程PPT教学课件(双语版)第十章 逆境生理.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第十三章 植物的抗性生理.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第十章 植物的生长生理.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第七章 植物体内的细胞信号转导.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第十二章 植物休眠、衰老与脱落.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第十一章 植物的生殖生理.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第八章 植物生长物质.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第五、六章 植物体内有机物的代谢与运输.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第九章 光形态建成.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第三章 植物的光合作用.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第二章 植物的矿质营养.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第一章 植物的水分代谢.ppt
- 酒泉职业技术学院:《植物生理学》(PPT课件)第四章 植物的呼吸作用.ppt
- 西华大学生物工程学院:《微生物学》第12章 微生物生态(车振明).ppt
- 西华大学生物工程学院:《微生物学》第10章 微生物与基因工程(车振明).ppt
- 《微生物生态学——Microbial Ecology》第三讲 微生物之间及其与动、植物的相互作用.ppt
- 北京大学:《细胞生物学 Cell Science》课程教学资源(教案讲义,共十三章).doc
- 《人类遗传学导论》PPT教学课件:第二章 生命从一个细胞开始.ppt
- 安徽医科大学:《神经生理学》第十章 神经系统.ppt
- 《环境工程微生物学》课程PPT教学课件(讲稿)绪论.ppt
- 《环境工程微生物学》课程PPT教学课件(讲稿)第一章 病毒 第一节 概述 第二节 毒粒的性质 第三节 病毒的复制.ppt
- 西华大学微生物遗传 生物工程学院:《微生物学》第八章 微生物遗传(车振明).ppt
- 北京大学:《发育生物学 Developmental Biology》课程教学资源(PPT课件)第七章 性别决定及生殖发育 Sex determination and reproduction.ppt
- 北京大学:《发育生物学 Developmental Biology》课程教学资源(PPT课件)第八章 胚后生长及衰老 Post-embryonic Growth and Aging.ppt
- 北京大学:《发育生物学 Developmental Biology》课程教学资源(PPT课件)第六章 发育中细胞分化机制.ppt
- 清华大学:《生物化学》课程PPT教学课件(英文版)Carbohydrates.ppt
- 清华大学:《生物化学》课程PPT教学课件(英文版)Nucleotides and Nucleic Acids(1/2).ppt
- 清华大学:《生物化学》课程PPT教学课件(英文版)Nucleotides and Nucleic Acids(2/2).ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 7 Interactions of Phagocytes and Other Immunological Cells.ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 9 Bacterial Toxins.ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 10 Staphylococci and Streptococci.ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 11 Neisseriaceae.ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 12 Enterobacteriaceae.ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 13 Pseudomonaceae.ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 14 Legionella.ppt
- 《微生物学》课程PPT课件讲稿(英文版)Lecture 1 Microbial Pathogenesis and Host-Parasite Relationships.ppt