Chapter 細胞骨§6.1細胞骨架的概Thecytoskeletonisthecomplexnetwork（復(fù)雜網(wǎng)絡(luò)）ofproteinfilaments（蛋白纖維）thatextendthroughouttheeukaryoticcell（真核細Ahighlydynamicstructure（動態(tài)結(jié)構(gòu)）thatreorganizescontinuouslyasthecellchangesshape,divides,andrespondstoi interactwithenvironmentdirectmovementsintermediatefilament（中等纖維nuclearmatrix（核基質(zhì)nuclearlamina（核纖層肌動肌動蛋白微中間纖two-strandedhelicallong,hollowcylindersattachedtoamicrotubuleorganizingcenter(MTOC)Intermediateforma中等纖肌動蛋白絲質(zhì)網(wǎng)絡(luò)末中間纖§6.2.1≥5%oftotalActinmoleculeα-invarioustypesofmusclecellsβ-andγ-innonmusclecells

肌動蛋白負正動態(tài)結(jié)

Ca2+,lowNa+,ATPandMg2+andhighNa+,

G-肌動蛋白的結(jié)負負正正解聚作聚解聚作聚合incorporatedinto蛋白質(zhì)結(jié)合，使肌蛋白不能與ADP結(jié)合肌動白絲的

肌動蛋白結(jié)合點上結(jié)合了其他蛋能夠聚 不能聚§6.2.2microfilament-associatedprotein（MAP,微絲結(jié)合蛋白）肌動蛋白纖維的三種排列方式應(yīng)力纖

偽細胞皮收縮 膠狀網(wǎng)

緊密平行α-α-輔肌動蛋 Lightgreen—α-helicalmotifsDarkgreen—β-sheetmotifs肌球蛋白:依賴于微絲的分子馬肌肌球蛋白肌動蛋白結(jié)合位ATP結(jié)合位肌球蛋500個氨基肌球蛋白-氨氨基末繞線式α螺輕羧基頸肌球蛋白-II肌球蛋白輕 肌動蛋白結(jié)合位磷酸

自組

15-20肌球蛋白非活化狀態(tài)：輕鏈未活化狀態(tài)：輕鏈磷肌球蛋白-肌球蛋白-肌球蛋白-質(zhì)質(zhì)整合蛋細胞結(jié)合到胞外基細胞胞外基 纖連蛋粘著連肌動蛋α-輔肌動蛋封端蛋

紐蛋樁蛋一種與細胞粘著有關(guān)纖連蛋白受體（整合蛋白纖連蛋MAPs蛋白質(zhì)功 舉 形狀，大小和分子質(zhì)量上的比

與肌動蛋互作用的加強微

肌動原肌球蛋

負 正

亞單微絲

毛緣蛋α-輔肌動蛋將微絲相連形成滑動微

肌球蛋白-微絲結(jié)合到質(zhì)膜上的位點血影蛋固定肌動固定肌動蛋單微絲結(jié)合蛋白間的相互作細絲蛋 相連成網(wǎng)肌動蛋原肌球蛋

收縮性肌動蛋白微絨無定型組織，深 肌動蛋白絲質(zhì)側(cè)臂（肌白-1，鈣調(diào)蛋白橫向連接（絨毛蛋白，毛緣蛋白細收縮培養(yǎng)纖維原應(yīng)力§6.2.3肌alsocalledmusclefibersbythefusionofmanyseparatecellsthenucleiareretainedinthislargecellandliejustbeneaththeplasmathebulkofthecytoplasmismadeupof肌纖細胞肌原纖 Severalcentimeterslong肌小 暗 亮A I

細纖維（肌動蛋白 contractileunitofmyofibrilZdisc（Z盤ateitherend entsiteforactinMline（M線thelocationofspecificproteinsthatlink filamentstoeachotherLightband（明帶containonlyactinDarkband（暗帶locationof 雙股α-

氨基末輕 肌球蛋白 aggregatetogetherbymeansoftheirtailHeadsof projectingtotheBarezoneinthecenterofthefilament tirely肌小肌肌球蛋白粗絲在肌小Z盤是肌動蛋白絲的正肌動蛋白絲的負TheplusendofeachactinfilamentisembeddedintheZdiscTheminusendpointstowardthemyosin肌肉收amyosinheadlackingaboundnucleotideislockedtightlyontoanactinfilament ATPbindstothemyosinchangetheconformationoftheactin-bindingreducestheaffinityoftheheadforactinandallowsittomovealongthefilamenthydrolysisofATPADPandPiremaintightlyboundtotheweakbindingofmyosinheadtoanewsiteontheactincausesthereleaseofPiforce-generatingchangeinheadregainsitsoriginalconformation,losesmyosinheadmovedtoanewpositionontheactin,isagainlockedtightlytotheactin肌動蛋白負 正結(jié) 肌球蛋白部松ATP頭部豎產(chǎn)生動位點形成弱的結(jié)Ca2+肌原纖Ca質(zhì)膜上內(nèi)陷的橫向電壓敏感

去極化的T－微管細胞肌質(zhì)網(wǎng)

Ca離 通肌鈣蛋白和肌球蛋白調(diào)節(jié)骨骼肌收縮時的肌鈣蛋白復(fù)合肌動蛋

原肌球蛋

原肌球蛋白阻礙球蛋白接合

DefinitiveandpositedHCMSeidmanetal.,CircRes2011,108:743-HollowΦ24onlyineucaryoticSpidle（紡錘體Basalbody（基粒Centrosome（中心粒Cilia（纖毛）,flagemmae（鞭毛Axon（軸突§6.3.1Tubulin（微管蛋白Heterodimer(αbasicunitofmicrotubuleα-tubulin:450aa,50KDβ-tubulin:455aaacidicC-αβ αβ αβmicrotubuleiscomposedof13原纖微管蛋白分裝Basalbody

間期細

纖毛Minusend(-)inPlusend(+)neartheplasma

期細紡神經(jīng)細中心GTP-containingsubunitsareforcedintoalinearconformationcurvedconformationTubulinconcentration:GTPhydrolysisafterpolymerizationdestabilizes微管蛋白二可交換的直原纖

GTPGTP水解改變亞單位構(gòu)并減弱聚合物之間的彎曲的原包含GDP-微管蛋白二解 的微管區(qū)域較不穩(wěn)GDP-GTP生 降Microtubule-associatedproteins(MAPs,微管相關(guān)蛋白)BindingtoModifymicrotubules’Microtubulemotorproteins（微管動力蛋白正 負驅(qū)動蛋 動力蛋Kinesin（驅(qū)動蛋白Dynein（動力蛋白 enttomicrotubulesinanATP-dependentfashion otorproteinhastwoheavychainsandseveralsmalllightchainsEachheavychainformsaglobularheadthatinteractswithmicrotubulesMotorproteinwalksATP-dependentlyalongmicrotubulesMotorproteinmovealong（動力蛋白沿著微管移動貨貨物分受驅(qū)動動力蛋負正動力蛋微受貨物動力KinesinmovetowardtheplusendofaDyneinmovetowardtheminusVesicletransportintwo驅(qū)動蛋白沿微管運動的步行?！?.3.2cilia（纖毛）andArrangementofmicrotubulesinaciliumor

ninespecialdoubletmicrotubulesarearrangedinaringaroundapairofsinglemicrotubulessinglecompletemicrotubule(13doubletonecompletemicrotubule(13subunits)onepartialmicrotubule(11subunits)Dyneindrivesthemovementsofcilia馬達蛋白介導(dǎo)的紡錘體的行§6.3.3centrioles（中心粒）andbasalbody（基粒）Cylindricalstructure（柱狀結(jié)構(gòu)~0.2μmwideand0.4μmninegroupsofthreemicrotubules,fusedintotripletsformthewalloftheadjacenttripletsarelinkedatintervalsalongtheirlengthDuplicationof thetwomembersofapairThenadaughtercentrioleisformedperpendiculartoeachoriginalcentrioleAnimmaturecentriolecontainsaninefoldsymmetricarrayofsinglemicrotubules icrotubuleactsasatemplatefortheassemblyofthetripletmicrotubuleofmaturecentrioles.Anewlyreplicatedpairof §6.4intermediatefilaments§6.4.1cytosolicIfs（細胞質(zhì)Monomer（單體C-terminalglobulartailcenterelongatedrodDimer（二聚體Tetramer（四聚體side-by-sideinastaggeredfashionwiththeirN-andC-terminalpointinginopposite(antiparallel)vianon-covalentRopelikeIF（繩狀end-to-endandside-by-sidevianon-covalentbondingα螺旋區(qū)雙股螺旋的二聚雙股螺旋二聚體交錯兩個四聚體組合在PropertiesanddistributionofTissuespecific（組織特異Evol