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RESEARCH PRODUCT
Lysosomal trafficking in rat cardiac myocytes.
Ari-pekka J. HuovilaMerja A. SurkkaAntero SalminenIlmari JokinenVarpu Marjomäkisubject
medicine.medical_specialtyHistologyCathepsin LImmunoblottingFluorescent Antibody TechniqueReceptors Cell SurfaceMitochondrionMitochondria HeartReceptor IGF Type 2Cathepsin LImmunolabelingsymbols.namesakeAntigens CDLysosomal-Associated Membrane Protein 1Internal medicineLysosomeEndopeptidasesmedicineAnimalsFrozen SectionsMyocyteReceptorchemistry.chemical_classificationMembrane GlycoproteinsbiologyMyocardiumLysosome-Associated Membrane GlycoproteinsIntracellular MembranesGolgi apparatusCathepsinsRatsCell biologyCysteine EndopeptidasesMicroscopy ElectronEndocrinologymedicine.anatomical_structureAnimals NewbornLiverchemistrybiology.proteinsymbolsCattleAnatomyLysosomesGlycoproteindescription
By immunolabeling of cryosections, we have characterized in rat cardiac myocytes the cation-independent mannose-6-phosphate receptor (MPR), a lysosomal membrane glycoprotein, lgp120, and a lysosomal enzyme, MEP (homologous to cathepsin L). Most of the MPR label was located in large membrane-filled structures (MPR structures) in large clusters of mitochondria adjacent to but distinct from the Golgi complex. Lpg120 and MEP showed typical lysosomal localization throughout the cell, often associated with regions that appeared to contain autophagosome-like structures. In addition, MEP and lgp120 co-localized within MPR structures. MEP and MPR were localized inside the lumen of MPR structures. MPR was associated mostly with inner membranes, whereas lgp120 was predominantly bound to the outer limiting membrane. MPR, lgp120, and MEP were not detected in Golgi stacks, but some labeling was seen in the putative TGN. Our data suggest that the MPR structures are prelysosomes involved in lysosomal enzyme targeting in rat cardiac myocytes.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 1990-08-01 | Journal of Histochemistry & Cytochemistry |