(完整PPT)第七章-细胞基质与细胞内膜系统-细胞生物学课件.ppt

1、Cytoplasmic matrix and Endomembrane systemChapter 7 Cytoplasmic matrix Endoplasmic reticulum,ER Golgi body or Golgi apparatus Lysosome Peroxisome or microbody Mitochodrion and chloroplastThe Structure of a bacteriumThe Compartmentalization of CellsAll Eucaryotic Cells Have the Same Basic Set of Memb

2、rane-enclosed Organellesor cytoplasmic matrix71 Cytoplasmic marix and its function Connotation Cytoplasmic matrix and Cytosol Function1.Synthesis of protein and Fatty acid2.Organizers of cell structure system3.Modification and degradation of proteinsModification of proteins Phosphorylation and depho

3、sphorylation (Ser,Thr,Tyr)Glycosylation Methylation AcylationDegradation of proteins Denatured or misfolded protein refolding Heat shock protein,HSP Protein lifetime controls The first amino acid:Met,Ser,Thr,Ala,Val,Cys,Gly or Pro aminoacyl-tRNA-protein transferase Degradation of denatured and misfo

4、lded proteins Ubiquitin and proteasome-mediated pathwayStructure of Ub and Ubl proteins.a)All of them have a commonsecondary structure.b)Superposing ribbon drawings of Ub and Ublproteins.Schematic representation of the structure of 20S and 26S proteasomes and regulatory particles.Model of 20S protea

5、some assembly.a)Scheme of assembly of the proteasome from the archaeon Thermoplasma acidophilum.b)Scheme of assembly of the eukaryotic proteasome.The 20S proteasome entrance.a)Three-dimensional model of a ring of a-subunits of the 20S proteasomeMolecular arrangement of the 19S regulatory particleFun

6、ctions of cytoplasmic matrixThe protein synthesis,modification and degradationCells carefully monitor the amount of misfolded proteins.An accumulation of misfolded proteins in the cytosol triggers a heat-shock response,which stimulates the transcription of genes encoding cytosolic chaperones that he

7、lp to refold the proteins.Topological relationships between compartments of the secretory and endocytic pathways in a eucaryotic cell72.Endoplasmic reticulum,ER Morphology and structure of the endoplasmic reticulum.Membrane-bound Ribosomes Define the Rough ER,rERTranslocon,=2nmSmooth ER Is Abundant

8、in Some Specialized CellsRough and Smooth Regions of ER Can Be Separated by CentrifugationThe functions of the endoplasmic reticulum rER and protein synthesis sER and lipid synthesis Protein modification and processing Folding and assembly of nascent peptides Calcium store磷脂转位蛋白（phospholipid translo

9、cator）磷脂交换蛋白（phospholipid exchange proteins，PEPs）Protein modification and processing Glycosylation N-linked glycosylation（Asn-X-Ser/Thr）and O-linked glycosylation Protein folding and assembly Disulfide bond formation Secretory vesiclesTranslocated Polypeptide Chains Fold and Assemble in the Lumen of

10、 the Rough ERN-linked Oligosaccharide磷酸多萜醇ER stress and its signal-regulatedUnfolded protein or misfolded proteins trigger ER stressCholesterol deficiency trigger ER stressEndoplasmic reticulum stress induced apoptosisendoplasmic reticulum stress，ERS需肌醇酶1（inositol requiring enzymel，Ire1）、类PKR似的内质网激酶

11、（PKR-like endoplasmic reticulum kinase，PERK）和激活性转录因子6（activating transcription factor 6，ATF6）为URP信号通路中起感受器的作用28S rRNAeIF2-PSterol Regulatory Element Binding Protein,SREBPImproperly Folded Proteins Are Exported from the ER and Degraded in the CytosolER associated degradation,ERADCell Life and Death D

12、ecisions3.Golgi complex Camillo Golgi was born in July 1843 in the village of Corteno,Lombardy.The village is now named Corteno Golgi in his honour.He spent much of his career studying the central nervous system,tissue staining.He discovered a method of staining nervous tissue which would stain a li

13、mited number of cells at random,in their entirety.This enabled him to view the paths of nerve cells in the brain for the first time.He called his discovery the“Black reaction”,which later received his name Golgi stain.The black reaction consisted in fixing silver chromate particles to the neurilemma

14、 by reacting silver nitrate with potassium dichromate.This resulted in a stark black deposit on the soma as well as on the axon and dendrites,providing an exceedingly clear and well contrasted picture of neuron against a yellow background.The ability to visualize separate neurons led to the eventual

15、 acceptance of the neuron doctrine.Using his staining technique,Golgi identified the intracellular reticular apparatus in 1898 which bears his name,the Golgi apparatus.Golgi,together with Santiago Ramn y Cajal,received the Nobel Prize in Physiology or Medicine in 1906 for his studies of the structur

16、e of the nervous system.Golgi died in Italy,on January 21,1926.1.Morphology and polarity of Golgi complexa)Cis cisternae of Golgi complex:reduced osmium tetroxide();b)Reaction for enzyme mannosidase II,localized in the medial;c)Reaction for enzyme nucleoside diphosphatase,localized in the trans cist

17、ernae.Regional differences in membrane compositionacross the Golgi stackv Transport within the Golgi apparatus:Two possible models explaining the organization of the Golgi complex and the transport from one cisterna to the next.十 十 十 2.Golgi BiogenesisNature 418:548,2002Stable expression of mammalia

18、n Golgi proteins.a,b,Overlaid immunofluorescence and phase images of GRASPYFP(a)and NAGTIYFP(b)in stable,transgenic cell lines of Toxoplasma gondii.ch,Immunofluorescence images of a transgenic cell line expressing both GRASPCFP(green)and NAGTIYFP(red)before(ce)or after(fh)treatment with 5mg/ml BFA f

19、or 10 min at 37C.Merged images are shown on the right.Asterisks indicate a secreted form of NAGTIYFP that accumulates in the parasitophorous vacuole.Scale bars,5mm.Golgi apparatus and cell secretory activity3.The Functions of Golgi complexFigure 13-24b Molecular Biology of the Cell(Garland Science 2

20、008)vGolgi complex and cells secretionContinual,unregulated discharge of material from the cellsThe discharge of products stored in cytoplasmic granules,in response to appropriate stimuli.Figure 13-31 Molecular Biology of the Cell(Garland Science 2008)The protein glycosylation its modifiedOligosacch

21、aride processing in Golgi compartmentsvGlycosylation in the Golgi complexGolgi complex plays a key role in the assembly of the carbohydrate component of glycoproteins and glycolipids.Function of glycosylationpromotion of protein folding and enhancing the stability of the glycoprotein IgG and Hemaggl

22、utinin fibronectin,FN CaluDifferent proteins carrying different flags in order to facilitate the sorting and packaging作业：简述高尔基体的结构组织及囊膜间蛋白质转运（可能）的机制Involved in differentiation,development,signal communication and other processGene knockout causes embryonic lethalityl Oligosaccharyl transferasel Mann

23、oprotein GlcNAc transferasel Alpha-glucosidase IIBlood group antigensKarl Landsteiner(June 14,1868 June 26,1943),was an Austrian biologist and physician.He is noted for having first distinguished the main blood groups in 1900,having developed the modern system of classification of blood groups from

24、his identification of the presence of agglutinins in the blood,In 1930 he received the Nobel Prize in Physiology or Medicine.在ABO抗原的生物合成中三个等位基因ABO及H控制着A、B抗原的形成。ABO抗原的前体是H抗原；A基因编码一种叫N-乙酰半乳糖胺转移酶的蛋白质（A 酶），能把H抗原转化成A抗原；B基因编码一种叫半乳糖转移酶的蛋白质（B酶），能把H抗原转化成B抗原；O基因不能编码有活性的酶，而只有H抗原。Packing and sorting pathways of

25、 lysosomal enzymesThe transport of newly synthesized lysosomal hydrolases to lysosome.Figure 13-43 Molecular Biology of the Cell(Garland Science 2008)The structure of mannose 6-phosphate on a lysosomal hydrolaseFigure 13-45 Molecular Biology of the Cell(Garland Science 2008)The recognition of a lyso

26、somal hydrolase.74 Lysosome Lysosomes are cellular organelles that contain acid hydrolase enzymes that break down waste materials and cellular debris.These are non-specific.They are found in animal cells,while their existence in yeasts and plants are disputed.Figure 13-3 Molecular Biology of the Cel

27、l(Garland Science 2008)Figure 13-38 Molecular Biology of the Cell(Garland Science 2008)A model for lysosome maturationFigure 13-37 Molecular Biology of the Cell(Garland Science 2008)The location of acid phosphataseFigure 13-39 Molecular Biology of the Cell(Garland Science 2008)Figure 13-41 Molecular

28、 Biology of the Cell(Garland Science 2008)A model of autophagyThe lysosomals functionFigure 13-42 Molecular Biology of the Cell(Garland Science 2008)Three pathways to degradation in lysosomesFigure 13-46 Molecular Biology of the Cell(Garland Science 2008)Phagocytosis by a macrophage.Figure 13-47a Mo

29、lecular Biology of the Cell(Garland Science 2008)A neutrophil reshaping a plasma membrane during phagocytosis.Pseudopod extention and phagosome formation are driven by actin polymerization and reorganization,which respond to the accumulation of specific phosphoinositides in the membrane of the formi

30、ng phagosome.Figure 13-48 Molecular Biology of the Cell(Garland Science 2008)The formation of clathrin-coated cesicles fron the plasmaFigure 13-49 Molecular Biology of the Cell(Garland Science 2008)Primary lysosomes and secondary lysosome75 Peroxisome or microbodyFigure 12-30 Molecular Biology of the Cell(Garland Science 2008)In rat liver cellFigure 12-32a Molecular Biology of the Cell(Garland Science 2008)Figure 12-32b Molecular Biology of the Cell(Garland Science 2008)乙醛酸循环体（glyoxysome）A model that explains how peroxisomes proliferate and how new peroxisomes may arise