{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,7]],"date-time":"2026-07-07T09:40:29Z","timestamp":1783417229522,"version":"3.54.6"},"reference-count":49,"publisher":"The Company of Biologists","issue":"2","license":[{"start":{"date-parts":[[1992,2,1]],"date-time":"1992-02-01T00:00:00Z","timestamp":696902400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/www.biologists.com\/user-licence-1-1\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[1992,2,1]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n               <jats:p>A detailed morphological and tracer study of endocytosis via coated pits in Paramecium multimicronucleatum was undertaken to compare endocytic processes in a free-living protozoon with similar processes in higher organisms. Permanent pits at the cell surface enlarge, become coated and give rise to coated vesicles (188\u00b141 nm in diameter) that enclose fluid-phase markers such as horseradish peroxidase (HRP). Both the pits and vesicles are labeled by the immunogold technique when a monoclonal antibody (mAb) raised against the plasma membrane of this cell is applied to cryosections. The HRP is delivered to an early endosome compartment, which also shares the plasma membrane antigen. The early endosome, as shown in quick-freeze deep-etch replicas of chemically unfixed cells, is a definitive non-reticular compartment composed of many individual flattened cisternal units of 0.2 to 0.7 \u03bcm diameter, each potentially bearing one or more \u223c80-nm-wide coated \u00e9vaginations. These coated \u00e9vaginations on the early endosomes contain HRP but are not labeled by the mAb. The coated \u00e9vaginations pinch off to form a second group of coated vesicles (90\u00b117 nm in diameter), which can be differentiated from those formed from coated pits by their smaller size, absence of plasma membrane antigen and their location somewhat deeper into the cytoplasm. This study shows a striking similarity between protozoons and mammalian cells in their overall early endosomal machinery and in the ability of early endosomes to sort cargo from plasma membrane components. The vesicles identified in this study form two distinct populations of putative shuttle vesicles, pre-endosomal (large) and early endosome-derived vesicles (small), which facilitate incoming and outgoing traffic from the early endosomes.<\/jats:p>","DOI":"10.1242\/jcs.101.2.449","type":"journal-article","created":{"date-parts":[[2021,4,25]],"date-time":"2021-04-25T15:20:41Z","timestamp":1619364041000},"page":"449-461","source":"Crossref","is-referenced-by-count":32,"title":["Endosomal system of Paramecium: coated pits to early endosomes"],"prefix":"10.1242","volume":"101","author":[{"given":"Richard D.","family":"Allen","sequence":"first","affiliation":[{"name":"University of Hawaii, Honolulu 1 Pacific Biomedical Research Center and Department of Microbiology , , Hawaii 96822, USA"},{"name":"University of Hawaii, Honolulu 1 Pacific Biomedical Research Center and Department of Microbiology , , Hawaii 96822, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christopher C.","family":"Schroeder","sequence":"additional","affiliation":[{"name":"2 Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusettes 01545, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Agnes K.","family":"Fok","sequence":"additional","affiliation":[{"name":"University of Hawaii, Honolulu 1 Pacific Biomedical Research Center and Department of Microbiology , , Hawaii 96822, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"237","published-online":{"date-parts":[[1992,2,1]]},"reference":[{"key":"2023073001045153700_JOCES_101_2_449C1","doi-asserted-by":"crossref","first-page":"120","DOI":"10.1083\/jcb.49.1.1","article-title":"Fine structure of membranous and microfibrillar systems in the cortex of Paramecium caudatum","volume":"49","author":"Allen","year":"1971","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C2","first-page":"254","article-title":"Freeze-fracture evidence for intramembrane changes accompanying membrane recycling in Paramecium","volume":"12","author":"Allen","year":"1976","journal-title":"Cytobiologie"},{"key":"2023073001045153700_JOCES_101_2_449C3","first-page":"657","article-title":"Membranes of ciliates: ultrastructure, biochemistry and fusion","volume-title":"Membrane Fusion","author":"Allen","year":"1978"},{"key":"2023073001045153700_JOCES_101_2_449C4","doi-asserted-by":"crossref","first-page":"4","DOI":"10.1007\/978-3-642-73086-3_2","article-title":"Cytology","volume-title":"Paramecium","author":"Allen","year":"1988"},{"key":"2023073001045153700_JOCES_101_2_449C5","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1242\/jcs.45.1.131","article-title":"Membrane recycling and endocytosis in Paramecium confirmed by horseradish peroxidase pulse-chase studies","volume":"45","author":"Allen","year":"1980","journal-title":"J. Cell Sci."},{"key":"2023073001045153700_JOCES_101_2_449C6","doi-asserted-by":"crossref","first-page":"1955","DOI":"10.1083\/jcb.99.6.1955","article-title":"Retrieval of lysosomal membrane and acid phosphatase from phagolysosomes of Paramecium caudatum","volume":"99","author":"Allen","year":"1984","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C7","doi-asserted-by":"crossref","first-page":"2233","DOI":"10.1083\/jcb.108.6.2233","article-title":"An investigation of mitochondrial inner membranes by rapid-freeze deep-etch techniques","volume":"108","author":"Allen","year":"1989","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C8","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1177\/37.2.2911005","article-title":"Intracellular binding of wheat germ agglutinin by Golgi complexes, phagosomes and lysosomes of Paramecium multimicronucleatum","volume":"37","author":"Allen","year":"1989","journal-title":"J. Histochem. Cytochem."},{"key":"2023073001045153700_JOCES_101_2_449C9","doi-asserted-by":"crossref","first-page":"663","DOI":"10.1016\/0092-8674(83)90052-1","article-title":"Recycling receptors: the round-trip itinerary of migrant membrane proteins","volume":"32","author":"Brown","year":"1983","journal-title":"Cell"},{"key":"2023073001045153700_JOCES_101_2_449C10","first-page":"103","article-title":"Dissection of endosomes","volume-title":"Intracellular Trafficking of Proteins","author":"Courtoy","year":"1989"},{"key":"2023073001045153700_JOCES_101_2_449C11","doi-asserted-by":"crossref","first-page":"2258","DOI":"10.1073\/pnas.80.8.2258","article-title":"pH and the recycling of transferrin during receptor-mediated endocytosis","volume":"80","author":"Dautry-Varsat","year":"1983","journal-title":"Proc. Nat. Acad. Sci. USA"},{"key":"2023073001045153700_JOCES_101_2_449C12","doi-asserted-by":"crossref","first-page":"395","DOI":"10.1111\/j.1432-1033.1987.tb13713.x","article-title":"Relations between plasma membrane and lysosomal membrane. I. Fate of covalently labelled plasma membrane protein","volume":"170","author":"Draye","year":"1987","journal-title":"Eur. J. Biochem."},{"key":"2023073001045153700_JOCES_101_2_449C13","doi-asserted-by":"crossref","first-page":"463","DOI":"10.1111\/j.1550-7408.1979.tb04654.x","article-title":"Axenic Paramecium caudatum. I. Mass culture and structure","volume":"26","author":"Fok","year":"1979","journal-title":"J. Protozoal."},{"key":"2023073001045153700_JOCES_101_2_449C14","first-page":"301","article-title":"The lysosome system","volume-title":"Paramecium","author":"Fok","year":"1988"},{"key":"2023073001045153700_JOCES_101_2_449C15","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1016\/S0074-7696(08)60671-3","article-title":"The phagosome-lysosome membrane system and its regulation in Paramecium","volume":"123","author":"Fok","year":"1990","journal-title":"Int. Rev. Cytol."},{"key":"2023073001045153700_JOCES_101_2_449C16","first-page":"27","article-title":"Modulation of the digestive lysosomal system in Paramecium caudatum. II. Physiological effects of cytochalasin B, colchicine and trifluoperazine","volume":"37","author":"Fok","year":"1985","journal-title":"Eur. J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C17","doi-asserted-by":"crossref","first-page":"216","DOI":"10.1111\/j.1550-7408.1984.tb02951.x","article-title":"Acid phosphatase in the digestive vacuoles and lysosomes of Paramecium caudatum: a timed study","volume":"31","author":"Fok","year":"1984","journal-title":"J. Protozoal."},{"key":"2023073001045153700_JOCES_101_2_449C18","doi-asserted-by":"crossref","first-page":"191","DOI":"10.1242\/jcs.91.2.191","article-title":"Characterization of monoclonal antibodies to trichocyst antigens in Paramecium","volume":"91","author":"Fok","year":"1988","journal-title":"J. Cell Sci."},{"key":"2023073001045153700_JOCES_101_2_449C19","doi-asserted-by":"crossref","first-page":"1767","DOI":"10.1083\/jcb.103.5.1767","article-title":"Transferrin receptor polarity and recycling accuracy in \u2018\u2018tight\u201d and \u201cleaky\u201d strains of Madin-Darby canine kidney cells","volume":"103","author":"Fuller","year":"1986","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C20","doi-asserted-by":"crossref","first-page":"1715","DOI":"10.1083\/jcb.104.6.1715","article-title":"Membranes of sorting organelles display lateral heterogeneity in receptor distribution","volume":"104","author":"Geuze","year":"1987","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C21","doi-asserted-by":"crossref","first-page":"277287","DOI":"10.1016\/0092-8674(83)90518-4","article-title":"Intracellular site of asialoglycoprotein receptor-ligand uncoupling: double-label immuno-electron microscopy during receptor-mediated endocytosis","volume":"32","author":"Geuze","year":"1983","journal-title":"Cell"},{"key":"2023073001045153700_JOCES_101_2_449C22","doi-asserted-by":"crossref","first-page":"193","DOI":"10.5962\/bhl.title.6273","volume-title":"Microscopic Histochemistry. Principles and Practice,","author":"Gomori","year":"1952"},{"key":"2023073001045153700_JOCES_101_2_449C23","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1146\/annurev.cb.05.110189.002321","article-title":"Membrane traffic in endocytosis: insights from cell-free assays","volume":"5","author":"Gruenberg","year":"1989","journal-title":"Annu. Rev. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C24","doi-asserted-by":"crossref","first-page":"731","DOI":"10.1083\/jcb.113.4.731","article-title":"The preendosomal compartment comprises distinct coated and noncoated endocytic vesicle populations","volume":"113","author":"Hansen","year":"1991","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C25","doi-asserted-by":"crossref","first-page":"1249","DOI":"10.1083\/jcb.103.4.1249","article-title":"Limited and selective transfer of plasma membrane glycoproteins to membrane of secondary lysosomes","volume":"103","author":"Haylett","year":"1986","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C26","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1083\/jcb.84.3.560","article-title":"Three-dimensional visualization of coated vesicle formation in fibroblasts","volume":"84","author":"Heuser","year":"1980","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C27","doi-asserted-by":"crossref","first-page":"389","DOI":"10.1083\/jcb.108.2.389","article-title":"Hypertonic media inhibit receptor-mediated endocytosis by blocking clathrin-coated pit formation","volume":"108","author":"Heuser","year":"1989","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C28","doi-asserted-by":"crossref","first-page":"335","DOI":"10.1038\/346335a0","article-title":"Movement of internalized ligand-receptor complexes along a continuous endosomal reticulum","volume":"346","author":"Hopkins","year":"1990","journal-title":"Nature"},{"key":"2023073001045153700_JOCES_101_2_449C29","doi-asserted-by":"crossref","first-page":"779","DOI":"10.1083\/jcb.40.3.779","article-title":"Cortical ultrastructure of Paramecium aurelia. Studies on isolated pellicles","volume":"40","author":"Hufnagel","year":"1969","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C30","doi-asserted-by":"crossref","first-page":"1548","DOI":"10.4049\/jimmunol.123.4.1548","article-title":"A new mouse myeloma cell line that has lost immunoglobulin expression but permits the construction of antibody-secreting hybrid cell line","volume":"123","author":"Kearney","year":"1979","journal-title":"J. Immunol."},{"key":"2023073001045153700_JOCES_101_2_449C31","doi-asserted-by":"crossref","first-page":"415","DOI":"10.1146\/annurev.bi.59.070190.002215","article-title":"Clathrin and associated assembly and disassembly proteins","volume":"59","author":"Keen","year":"1990","journal-title":"Annu. Rev. Biochem."},{"key":"2023073001045153700_JOCES_101_2_449C32","doi-asserted-by":"crossref","first-page":"4715","DOI":"10.1016\/S0021-9258(18)32481-5","article-title":"Receptor-mediated endocytosis of transferrin in K562 cells","volume":"258","author":"Klausner","year":"1983","journal-title":"J. Biol. Chem."},{"key":"2023073001045153700_JOCES_101_2_449C33","doi-asserted-by":"crossref","first-page":"1615","DOI":"10.1083\/jcb.108.5.1615","article-title":"Coat proteins isolated from clathrin coated vesicles can assemble into coated pits","volume":"108","author":"Mahaffey","year":"1989","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C34","doi-asserted-by":"crossref","first-page":"2899","DOI":"10.1073\/pnas.83.9.2899","article-title":"Three-dimensional structure of endosomes in BHK-21 cells","volume":"83","author":"Marsh","year":"1986","journal-title":"Proc. Nat. Acad. Sci. USA"},{"key":"2023073001045153700_JOCES_101_2_449C35","doi-asserted-by":"crossref","first-page":"255","DOI":"10.1016\/S0070-2161(08)60048-9","article-title":"The control of Early endosomes of Paramecium 461 membrane traffic on the endocytic pathway","volume":"29","author":"Mellman","year":"1987","journal-title":"Curr. Topics Membr. Transport"},{"key":"2023073001045153700_JOCES_101_2_449C36","first-page":"351","article-title":"Digestion","volume-title":"Chemical Zoology","author":"Millier","year":"1967"},{"key":"2023073001045153700_JOCES_101_2_449C37","doi-asserted-by":"crossref","first-page":"209","DOI":"10.1242\/jcs.63.1.209","article-title":"Coated pits and pinocytosis in Tetrahymena","volume":"63","author":"Nilsson","year":"1983","journal-title":"J. Cell Sci."},{"key":"2023073001045153700_JOCES_101_2_449C38","first-page":"107","article-title":"Membranous sacs associated with cilia of Paramecium","volume":"17","author":"Patterson","year":"1978","journal-title":"Eur. J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C39","doi-asserted-by":"crossref","first-page":"151","DOI":"10.1146\/annurev.cb.06.110190.001055","article-title":"Clathrin, adaptors and sorting","volume":"6","author":"Pearse","year":"1990","journal-title":"Annu. Rev. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C40","doi-asserted-by":"crossref","first-page":"1","DOI":"10.5962\/bhl.title.7050","volume-title":"Electron-Microscopic Structure of Protozoa,","author":"Pitelka","year":"1963"},{"key":"2023073001045153700_JOCES_101_2_449C41","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1016\/S0074-7696(08)60652-X","article-title":"Regulation of membrane fusion during exocytosis","volume":"119","author":"Plattner","year":"1989","journal-title":"Int. Rev. Cytol."},{"key":"2023073001045153700_JOCES_101_2_449C42","first-page":"571","article-title":"Ultrastructural aspects of exocytosis","volume-title":"Membrane Fusion","author":"Plattner","year":"1991"},{"key":"2023073001045153700_JOCES_101_2_449C43","doi-asserted-by":"crossref","first-page":"73","DOI":"10.1016\/0092-8674(88)90532-6","article-title":"Two distinct subpopulations of endosomes involved in membrane recycling and transport to lysosomes","volume":"52","author":"Schmid","year":"1988","journal-title":"Cell"},{"key":"2023073001045153700_JOCES_101_2_449C44","doi-asserted-by":"crossref","first-page":"2553","DOI":"10.1083\/jcb.111.6.2553","article-title":"Vesicle transport along microtubular ribbons and isolation of cytoplasmic dynein from Paramecium","volume":"Ill","author":"Schroeder","year":"1990","journal-title":"J. Cell Biol."},{"key":"2023073001045153700_JOCES_101_2_449C45","doi-asserted-by":"crossref","first-page":"492","DOI":"10.1111\/j.1550-7408.1966.tb01948.x","article-title":"Growth of particle-bearing and particle-free Paramecium aurelia in axenic culture","volume":"13","author":"Soldo","year":"1966","journal-title":"J. Proto tool."},{"key":"2023073001045153700_JOCES_101_2_449C46","doi-asserted-by":"crossref","first-page":"104","DOI":"10.1016\/0076-6879(86)34079-5","article-title":"Purification of brain microtubules and microtubule-associated protein 1 using taxol","volume":"134","author":"Vallee","year":"1986","journal-title":"Meth. Enzymol."},{"key":"2023073001045153700_JOCES_101_2_449C47","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/0014-4827(87)90257-6","article-title":"Delivery of internalized ricin from endosomes to cisternal Golgi elements is a discontinuous, temperature-sensitive process","volume":"171","author":"van Deurs","year":"1987","journal-title":"Exp. Cell Res."},{"key":"2023073001045153700_JOCES_101_2_449C48","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/S0074-7696(08)61336-4","article-title":"The ways of endocytosis","volume":"117","author":"van Deurs","year":"1989","journal-title":"Int. Rev. Cytol."},{"key":"2023073001045153700_JOCES_101_2_449C49","first-page":"52a","article-title":"Flow of membrane markers from the coated pits in Paramecium caudatum","volume":"101","author":"Westcot","year":"1985","journal-title":"J. Cell Biol."}],"container-title":["Journal of Cell Science"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.biologists.com\/jcs\/article-pdf\/101\/2\/449\/3089510\/joces_101_2_449.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/journals.biologists.com\/jcs\/article-pdf\/101\/2\/449\/3089510\/joces_101_2_449.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,30]],"date-time":"2023-07-30T01:05:15Z","timestamp":1690679115000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.biologists.com\/jcs\/article\/101\/2\/449\/23245\/Endosomal-system-of-Paramecium-coated-pits-to"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,2,1]]},"references-count":49,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1992,2,1]]}},"URL":"https:\/\/doi.org\/10.1242\/jcs.101.2.449","relation":{},"ISSN":["0021-9533","1477-9137"],"issn-type":[{"value":"0021-9533","type":"print"},{"value":"1477-9137","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,2,1]]}}}