{"action":"created","issue":{"url":"https://api.github.com/repos/geneontology/go-annotation/issues/1324","labels_url":"https://api.github.com/repos/geneontology/go-annotation/issues/1324/labels{/name}","comments_url":"https://api.github.com/repos/geneontology/go-annotation/issues/1324/comments","events_url":"https://api.github.com/repos/geneontology/go-annotation/issues/1324/events","html_url":"https://github.com/geneontology/go-annotation/issues/1324","id":112221625,"number":1324,"title":"gamma glutamyl transferase and glutahione hydrolase","user":{"login":"ValWood","id":7359272,"avatar_url":"https://avatars.githubusercontent.com/u/7359272?v=3","gravatar_id":"","url":"https://api.github.com/users/ValWood","html_url":"https://github.com/ValWood","followers_url":"https://api.github.com/users/ValWood/followers","following_url":"https://api.github.com/users/ValWood/following{/other_user}","gists_url":"https://api.github.com/users/ValWood/gists{/gist_id}","starred_url":"https://api.github.com/users/ValWood/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ValWood/subscriptions","organizations_url":"https://api.github.com/users/ValWood/orgs","repos_url":"https://api.github.com/users/ValWood/repos","events_url":"https://api.github.com/users/ValWood/events{/privacy}","received_events_url":"https://api.github.com/users/ValWood/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":4,"created_at":"2015-10-19T20:02:59Z","updated_at":"2015-10-21T07:03:54Z","closed_at":null,"body":"\r\nDoes anybody know  anything about  gamma-glutamyltranspeptidases ?\r\n\r\nIn pombe we have 2\r\nggt1 http://www.pombase.org/spombe/result/SPAC664.09\r\nand \r\nggt2 http://www.pombase.org/spombe/result/SPAC56E4.06c\r\n\r\nwe have annotated to \r\ngamma-glutamyltransferase activity\r\nand so has SGD\r\nhttp://www.yeastgenome.org/locus/YLR299W/overview#go\r\n\r\nbut EC mapping is to GO:0036374 glutathione hydrolase activity\r\n(these 2 terms do not appear to be related)\r\n\r\n\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/geneontology/go-annotation/issues/comments/149799802","html_url":"https://github.com/geneontology/go-annotation/issues/1324#issuecomment-149799802","issue_url":"https://api.github.com/repos/geneontology/go-annotation/issues/1324","id":149799802,"user":{"login":"ValWood","id":7359272,"avatar_url":"https://avatars.githubusercontent.com/u/7359272?v=3","gravatar_id":"","url":"https://api.github.com/users/ValWood","html_url":"https://github.com/ValWood","followers_url":"https://api.github.com/users/ValWood/followers","following_url":"https://api.github.com/users/ValWood/following{/other_user}","gists_url":"https://api.github.com/users/ValWood/gists{/gist_id}","starred_url":"https://api.github.com/users/ValWood/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/ValWood/subscriptions","organizations_url":"https://api.github.com/users/ValWood/orgs","repos_url":"https://api.github.com/users/ValWood/repos","events_url":"https://api.github.com/users/ValWood/events{/privacy}","received_events_url":"https://api.github.com/users/ValWood/received_events","type":"User","site_admin":false},"created_at":"2015-10-21T07:03:53Z","updated_at":"2015-10-21T07:03:53Z","body":" A really useful summary from Marie:\r\n\r\nThanks for reaching out to me. The link to my review that was included in the earlier post will provide a fairly compressive overview of the enzyme -  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4388159/\r\n\r\nThe answer answer to your questions: Gamma-glutamyl transferase and gamma-glutamyl transpeptidase  are alternative names for the same protein. There is actually a family of GGT enzymes and in vertebrates GGT1 is the enzyme that is referred to when people talk about GGT. There is also a GGT5 enzyme that is expressed and active, in humans there is a GGT2 gene that is expressed but inactive. (we have publications on both these enzymes). With regard to the activity of GGT it is a cell surface enzyme that hydrolyzes the gamma-glutamyl bond of extracellular gamma-glutamyl compounds. Glutathione is the most abundant substrate physiologically. In a test tube one can set up conditions in which the enzyme will transfer the gamma-glutamyl portion of the substrate to an acceptor molecule, but this requires non-physiologic conditions, including millmolar concentrations of an acceptor such as glygly. This reaction is used in assays to detect the presence of the enzyme, but is not a physiological function of GGT.    \r\n\r\n==\r\n@pgaudet  this is a really useful summary and references  for PAINTING these proteins\r\n\r\nI'm going to open a ticket on the ontology tracker to include this ref and add comments to the 2 terms about the physiological direction.\r\n\r\n"}}