{"id":1150,"date":"2019-06-05T17:35:49","date_gmt":"2019-06-05T09:35:49","guid":{"rendered":"http:\/\/www.bioactivescreeninglibrary.com\/?p=1150"},"modified":"2022-01-07T10:53:33","modified_gmt":"2022-01-07T02:53:33","slug":"experiments-spliced-mrna-transcripts-induction-vsg-rnai","status":"publish","type":"post","link":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/2019\/06\/05\/experiments-spliced-mrna-transcripts-induction-vsg-rnai\/","title":{"rendered":"Our experiments spliced mRNA transcripts after the induction of VSG RNAi"},"content":{"rendered":"

Therefore the ER stress caused by blocking VSG synthesis appears to use different pathways than those that trigger the spliced leader RNA silencing response in African trypanosomes. A second possible explanation for the observed translation arrest, is that trypanosomes always transiently arrest protein synthesis when they are in the precytokinesis stage of the cell-cycle. Earlier, it has been shown in mammalian cells that protein synthesis slows down when cells are in the G2\/M stage of the cellcycle. However in our case, this is unlikely to provide the explanation. After the induction of VSG RNAi, the stalled population of trypanosomes is up to 60% Gomisin-D<\/a> enriched for precytokinesis stage cells, but still contains cells in other stages of the cellcycle which normally would be expected to be translationally active. This scenario is not compatible with our observed block in protein synthesis down to less than 1\ufffdC4% normal levels. A third possibility is that the observed translation arrest is a general feature of RNAi phenotypes that result in growth inhibition and eventual death. This is not the case, as cells arrested as a consequence of another lethal phenotype do not show reduced levels of translation. In addition, we have no evidence that our cells are an obviously dying Danshensu<\/a> system within the 24 hour period used in these analyses. Our arrested cells are viable for relatively long periods, with virtually all cells intact and metabolically active after 24 hours. Endocytosis of FITC-tomato lectin appears unimpaired, and as shown here, there was no significant drop in transcription. In addition, the proteomic analysis did not detect changes in the most abundant proteins even in fully stalled cells, confirming that we are not looking at a system that is obviously falling apart. Last, arrested cells were able to reenter the cell-cycle when doxycycline was removed. We favour an explanation whereby induction of a VSG synthesis block triggers a stress response resulting in a global translation arrest. Although it is unclear what exactly is being “sensed” in this stress response pathway, our data is most compatible with a scenario whereby the cell senses the restriction occurring from the lack of deposition of VSG on the cell surface. The fact that downregulation of actin also triggers a severe translation arrest is compatible with this possibility. Does this arrest operate in vivo during an infection?<\/p>\n","protected":false},"excerpt":{"rendered":"

Therefore the ER stress caused by blocking VSG synthesis appears to use different pathways than those that trigger the spliced leader RNA silencing response in African trypanosomes. A second possible explanation for the observed translation arrest, is that trypanosomes always transiently arrest protein synthesis when they are in the precytokinesis stage of the cell-cycle. Earlier, … Continue reading “Our experiments spliced mRNA transcripts after the induction of VSG RNAi”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts\/1150"}],"collection":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/comments?post=1150"}],"version-history":[{"count":1,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts\/1150\/revisions"}],"predecessor-version":[{"id":1151,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/posts\/1150\/revisions\/1151"}],"wp:attachment":[{"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/media?parent=1150"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/categories?post=1150"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.bioactivescreeninglibrary.com\/index.php\/wp-json\/wp\/v2\/tags?post=1150"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}