{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,19]],"date-time":"2026-05-19T23:49:13Z","timestamp":1779234553763,"version":"3.51.4"},"update-to":[{"DOI":"10.1371\/journal.ppat.1012333","type":"new_version","label":"New version","source":"publisher","updated":{"date-parts":[[2024,7,10]],"date-time":"2024-07-10T00:00:00Z","timestamp":1720569600000}}],"reference-count":45,"publisher":"Public Library of Science (PLoS)","issue":"6","license":[{"start":{"date-parts":[[2024,6,27]],"date-time":"2024-06-27T00:00:00Z","timestamp":1719446400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["101842\/Z13\/Z"],"award-info":[{"award-number":["101842\/Z13\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100010269","name":"Wellcome Trust","doi-asserted-by":"publisher","award":["208780\/Z\/17\/Z"],"award-info":[{"award-number":["208780\/Z\/17\/Z"]}],"id":[{"id":"10.13039\/100010269","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plospathogens.org"],"crossmark-restriction":false},"short-container-title":["PLoS Pathog"],"abstract":"<jats:p>\n                    The bloodstream form of\n                    <jats:italic>Trypanosoma brucei<\/jats:italic>\n                    expresses large poly-\n                    <jats:italic>N<\/jats:italic>\n                    -acetyllactosamine (pNAL) chains on complex\n                    <jats:italic>N<\/jats:italic>\n                    -glycans of a subset of glycoproteins. It has been hypothesised that pNAL may be required for receptor-mediated endocytosis. African trypanosomes contain a unique family of glycosyltransferases, the GT67 family. Two of these, TbGT10 and TbGT8, have been shown to be involved in pNAL biosynthesis in bloodstream form\n                    <jats:italic>Trypanosoma brucei<\/jats:italic>\n                    , raising the possibility that deleting both enzymes simultaneously might abolish pNAL biosynthesis and provide clues to pNAL function and\/or essentiality. In this paper, we describe the creation of a\n                    <jats:italic>TbGT10<\/jats:italic>\n                    null mutant containing a single\n                    <jats:italic>TbGT8<\/jats:italic>\n                    allele that can be excised upon the addition of rapamycin and, from that, a\n                    <jats:italic>TbGT10<\/jats:italic>\n                    and\n                    <jats:italic>TbGT8<\/jats:italic>\n                    double null mutant. These mutants were analysed by lectin blotting, glycopeptide methylation linkage analysis and flow cytometry. The data show that the mutants are defective, but not abrogated, in pNAL synthesis, suggesting that other GT67 family members can compensate to some degree for loss of TbGT10 and TbGT8. Despite there being residual pNAL synthesis in these mutants, certain glycoproteins appear to be particularly affected. These include the lysosomal CBP1B serine carboxypeptidase, cell surface ESAG2 and the ESAG6 subunit of the essential parasite transferrin receptor (TfR). The pNAL deficient TfR in the mutants continued to function normally with respect to protein stability, transferrin binding, receptor mediated endocytosis of transferrin and subcellular localisation. Further the pNAL deficient mutants were as viable as wild type parasites\n                    <jats:italic>in vitro<\/jats:italic>\n                    and in\n                    <jats:italic>in vivo<\/jats:italic>\n                    mouse infection experiments. Although we were able to reproduce the inhibition of transferrin uptake with high concentrations of pNAL structural analogues (\n                    <jats:italic>N<\/jats:italic>\n                    -acetylchito-oligosaccharides), this effect disappeared at lower concentrations that still inhibited tomato lectin uptake, i.e., at concentrations able to outcompete lectin-pNAL binding. Based on these findings, we recommend revision of the pNAL-dependent receptor mediated endocytosis hypothesis.\n                  <\/jats:p>","DOI":"10.1371\/journal.ppat.1012333","type":"journal-article","created":{"date-parts":[[2024,6,27]],"date-time":"2024-06-27T17:04:12Z","timestamp":1719507852000},"page":"e1012333","update-policy":"https:\/\/doi.org\/10.1371\/journal.ppat.corrections_policy","source":"Crossref","is-referenced-by-count":8,"title":["Generation of a bloodstream form Trypanosoma brucei double glycosyltransferase null mutant competent in receptor-mediated endocytosis of transferrin"],"prefix":"10.1371","volume":"20","author":[{"given":"Samuel M.","family":"Duncan","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Carla Gilabert","family":"Carbajo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rupa","family":"Nagar","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Qi","family":"Zhong","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Conor","family":"Breen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Michael A. J.","family":"Ferguson","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3742-6502","authenticated-orcid":true,"given":"Calvin","family":"Tiengwe","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2024,6,27]]},"reference":[{"key":"ppat.1012333.ref001","doi-asserted-by":"crossref","first-page":"1743","DOI":"10.1042\/BCJ20210778","article-title":"Common and unique features of glycosylation and glycosyltransferases in African trypanosomes","volume":"479","author":"S. M. Duncan","year":"2022","journal-title":"Biochem. J"},{"key":"ppat.1012333.ref002","doi-asserted-by":"crossref","first-page":"865","DOI":"10.1074\/jbc.M411061200","article-title":"Trypanosoma brucei Glycoproteins Contain Novel Giant Poly-N-acetyllactosamine Carbohydrate Chains","volume":"280","author":"A. Atrih","year":"2005","journal-title":"J. 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