{"65810":{"#nid":"65810","#data":{"type":"event","title":"IBSI Distinguished Scientific Leader Lecture Series Presents:  Nobel Laureate Tim Hunt","body":[{"value":"\u003Cp\u003EDrs.\nYuhong Fan, Jeffrey Skolnick and the Integrative BioSystems Institute are\npleased to host Distinguished Scientific Leader Lecture speaker,\u0026nbsp;\u003Cstrong\u003EDr.\nTim Hunt\u003C\/strong\u003E,\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E2001 Nobel Prize Winner in Medicine and Principal\nScientist at Cancer Research UK, London Research Institute. His seminar will be\nheld on Wednesday, May 4, 2011 from 11:00 AM to 12:00 PM in the\u0026nbsp;\u003Cstrong\u003EMarcus\nNanotechnology Building, Room 1116\u003C\/strong\u003E. A reception honoring Dr. Hunt will be\nheld in the gallery immediately following the seminar. The title of his talk\nwill be \u201cSwitches and Latches: New Elements in the Control of Mitosis\u0022.\u003C\/p\u003E\n\n\u003Cp\u003EAbstract:\nThe process of mitosis involves a comprehensive reorganization of the cell:\nchromosomes condense, the nuclear envelope breaks down, the mitotic spindle is\nassembled, cells round up and release their ties to the substrate and so on and\nso forth. This reorganization is triggered by the activation of a protein\nkinase called Cyclin-Dependent Kinase 1 (CDK1). The end of mitosis is marked by\nthe proteolysis of the cyclin subunit of CDK1, which terminates kinase\nactivity. At this point, the phosphate moieties that altered the properties of\nhundreds of proteins to bring about the cellular reorganization are removed by\nprotein phosphatases. We recently began to pay attention to the control of\nthese protein phosphatases, conscious that it was likely that they were shut\noff as cells enter mitosis, and reactivated when mitosis is complete, allowing\nreturn to interphase. It is difficult to see how proteins could be fully\nphosphorylated if both kinases and phosphatases were simultaneously active (much\nas filling a wash basin requires not only turning on the water taps, but also\nputting in the plug). It emerged that at least one protein phosphatase,\nPP2A-B55, was shut off in mitosis. Depletion of this particular form of PP2A\naccelerated entry into mitosis, and blocked exit from mitosis. We have\ndiscovered how this phosphatase is regulated. It entails binding a small\ninhibitor protein (alpha-endosulfine or ARPP-19) that is phosphorylated by a\nprotein kinase called Greatwall that is itself a substrate of CDK1. Failure to\ninhibit PP2A-B55 causes arrest of the cell cycle in G2 phase. I will explain\nhow we found this out, and discuss the role of this particular control\nmechanism in the control of mitosis. The switches and latches of my title\nrefers to our still rather poor understanding of exactly how the timing of\nentry into mitosis is controlled, together with the realization that the\nGreatwall alpha-Endosulfine circuit is not only required for entering mitosis,\nbut also for staying there. Recent evidence from budding yeast suggests that\nthe same control module is involved in controlling the switch into quiescence\nwhen the yeast are starving, and not in the normal control of cell\ndivision.\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EPlease\nNote: Dr. Hunt\u0027s seminar is free and open to the campus community. No\nreservations are required, but please note that space is limited and seating is\non a first-come, first-served basis.\u003C\/p\u003E","summary":null,"format":"limited_html"}],"field_subtitle":"","field_summary":"","field_summary_sentence":[{"value":"Hunt is a Principal Scientist at Cancer Research UK and 2001 Nobel Prize Winner in Medicine or Physiology."}],"uid":"27199","created_gmt":"2011-04-27 12:51:50","changed_gmt":"2016-10-08 01:54:54","author":"Jessica Forness","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2011-05-04T12:00:00-04:00","event_time_end":"2011-05-04T14:00:00-04:00","event_time_end_last":"2011-05-04T14:00:00-04:00","gmt_time_start":"2011-05-04 16:00:00","gmt_time_end":"2011-05-04 18:00:00","gmt_time_end_last":"2011-05-04 18:00:00","rrule":null,"timezone":"America\/New_York"},"extras":["free_food"],"related_links":[{"url":"http:\/\/info.cancerresearchuk.org\/cancerandresearch\/ourcurrentresearch\/researchbygrantee\/dr-tim-hunt","title":"Profile, Cancer Research UK"},{"url":"http:\/\/www.london-research-institute.org.uk\/research\/loc\/london\/lifch\/huntt\/?source=research_portfolio\u0026view=LRI","title":"Profile, London Reseach Instiute"},{"url":"http:\/\/nobelprize.org\/nobel_prizes\/medicine\/laureates\/2001\/hunt-autobio.html","title":"Profile, Nobelprize.org"}],"groups":[{"id":"1182","name":"General"}],"categories":[],"keywords":[{"id":"7715","name":"Nobel Prize"},{"id":"12954","name":"Tim Hunt"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1795","name":"Seminar\/Lecture\/Colloquium"}],"invited_audience":[],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[{"value":"\u003Cp\u003EJessica Gilmore Forness\u003Cbr \/\u003E\nExecutive Assistant\u003Cbr \/\u003E\nIntegrative BioSystems Institute \u003Cbr \/\u003E\nPhone: (404) 407-8976 \u003Cbr \/\u003E\nE-mail: \u003Ca href=\u0022mailto:jessica.gilmore@biology.gatech.edu\u0022\u003Ejessica.gilmore@biology.gatech.edu\u003C\/a\u003E\u003Cbr \/\u003E\n\u003Ca href=\u0022http:\/\/www.ibsi.gatech.edu\/\u0022 title=\u0022http:\/\/www.ibsi.gatech.edu\/\u0022\u003Ehttp:\/\/www.ibsi.gatech.edu\/\u003C\/a\u003E\u003C\/p\u003E","format":"limited_html"}],"email":[],"slides":[],"orientation":[],"userdata":""}}}