◆Acommonfeatureforlysosomalenzymes：----containingmannose-6-phosphate(M6P,6-磷酸甘露糖)initsoligosaccharidechain，----ThereceptoroflysosomalenzymesspecificallybindingtoM6P(5)LysosomebiogenesisN-乙酰葡萄糖胺磷酸转移酶N-乙酰葡萄糖苷酶N-乙酰葡萄糖胺催化磷酸转移Phosphorylationofmannose:N-GlcNAcphosphotransferase(N-乙酰葡萄糖胺磷酸转移酶)◆signalpatch(信号斑)：存在于完成折叠的蛋白质中，由几个信号序列折叠在一起构成的三维结构。N-乙酰葡萄糖胺磷酸转移酶识别信号斑溶酶体酶合成及糖基化修饰寡糖链甘露糖残基磷酸化溶酶体酶分选磷酸基团被去除--初级溶酶体部分M6P受体也会到达细胞质膜M6P受体蛋白在pH6.5～7的条件下与M6P结合，在pH<=6条件下脱落◆Mannose-6-phosphate（M6P）pathway溶酶体酶的识别和分选缺损途径（defaultpathway）受体介导低pH时晚期内体晚期内体与溶酶体融合，将溶酶体酶送入溶酶体在І-细胞患者的某些细胞如肝细胞中，尽管由于N-乙酰葡萄糖胺磷酸转移酶的突变，溶酶体酶不能形成M6P标志，但溶酶体酶仍有正常溶酶体酶的补给--不依赖于M6P的分选途径。PLANTCELLVACUOLES2.Characteristicsofendomembranesystem◆Independent●enclosedcompartments●specializedfunction◆DynamicandInterdependent●Biosyntheticpathway●Secretorypathway●Endocytosispathway:◆Vesicletransport--transportwayofproteinsandlipids*adynamic,interconnectednetwork：proteinsortingProteinsortinginsidecell3.Biologicalsignificanceofendomembranesystems●formingsomefunctionallyspecializedcompartments----providemicroenvironmentwithinthecellforvarietiesofbiochemicalreactions.----raisingreactiveefficiencybyimprovingimportantmolecularconcentration.●improvingitsregulatorycapacitybyenlargingmembraneareaofmetabolism,whichprovidesattachmentbracketfortheenzyme●Functionasaintracellularmembranesystem----allthemembraneissynthesizedandassembleduniformly,therebykeepingintracellularmembranestructureinagreement.----intercoordinationinfunction—group-likemanagement----membranetraffic(膜流)bythesecretoryandendocyticpathwayskeepscellsyouthful--Membranetransformation.膜流（membraneflowormembranetraffic）：细胞的各种膜结构相互联系和转移现象称为膜流。内质网至...
