{"id":4869,"date":"2014-06-03T11:43:33","date_gmt":"2014-06-03T15:43:33","guid":{"rendered":"https:\/\/web.uri.edu\/inbre\/?page_id=4869"},"modified":"2014-06-03T11:43:33","modified_gmt":"2014-06-03T15:43:33","slug":"almeida","status":"publish","type":"page","link":"https:\/\/web.uri.edu\/riinbre\/research\/surf-training-award\/almeida\/","title":{"rendered":"Small molecule regulators of nicotinamide phosphoribosyltransferase (NAMPT)"},"content":{"rendered":"<p><strong>Investigator:<\/strong>\u00a0Karen Almeida, Rhode Island College<\/p>\n<p><strong>Scientific Theme:<\/strong>\u00a0Cancer<\/p>\n<p style=\"text-align: justify\"><strong>Abstract:\u00a0<\/strong>NAD+ is essential for life and therefore must be strictly monitored. NAD+ is widely used as the cofactor in\u00a0cell energy production and metabolism by providing high-energy electrons required for oxidation\/reduction\u00a0reactions. However, NAD+ concentration is diminished by its use as a substrate for enzymes such as poly\u00a0(ADP-ribose) polymerases (PARPs) and Sirtuins. In each case, the ADP-ribose portion of NAD+ is cleaved\u00a0from the nicotinamide (NAM) moiety. To restore NAD+, NAM is converted to nicotinamide mononucleotide\u00a0(NMN) by the rate-limiting enzyme Nicotinamide phosphoribosyltransferase (NAMPT) also called\u00a0NAmPRTase, Pre-B cell-enhancing factor (PBEF), or Vistafin. NAD+ is regenerated in the second step with\u00a0concomitant hydrolysis of ATP by the enzyme NMNAT. Within the NAD+ salvage pathway, NAMPT has\u00a0been shown to modulate the cellular NAD+ levels and therefore is a potential target for regulation by\u00a0inhibitors. NAMPT is a 55-kDa enzyme that forms a homodimer to generate two active sites. The channel\u00a0leading into the active site is primarily housed in one monomer with contributions at the active site from the\u00a0opposing monomer. NAMPT enzymatic activity as a phosphoribosyltransferase has been well established.\u00a0Little to no information is available regarding the dimerization and thus activation of the NAMPT monomers.\u00a0We hypothesize that the increased activity shown in our initial screens is the result of small molecule binding\u00a0to affect a shift in the monomer\/dimer equilibrium. In other words, these compounds are binding across the\u00a0dimerization plane, stabilizing the active dimer and thus increasing enzymatic activity. The overall goal of this\u00a0proposal is to determine which structural components of the two recently identified activators are required to\u00a0elicit the increase in NAMPT activity. This information can then direct the screening of drug libraries for\u00a0novel activators. We propose to 1) screen commercially available derivatives of the two known activators 2)\u00a0establish a method to monitor the monomer\/dimer equilibrium based on a Bimolecular Fluorescence\u00a0Complementation assay based on Enhanced Yellow Fluorescence Protein (EYFP). We anticipate identifying\u00a0several new compounds that influence NAMPT activity and\/or dimerization.<\/p>\n<p style=\"text-align: justify\"><strong>Human Health Relevance:\u00a0<\/strong>NAMPT is under investigation for its relevance to human disease states, including cancer, diabetes, and\u00a0heart disease. NAMPT inhibits apoptosis in cancer cells, necessary for the transition to a cancerous state.\u00a0Additionally, NAMPT activates the IL-6\/STAT3 cell survival pathway by a non-enzymatic mechanism. It is\u00a0likely that one or more of these pathways are affected by the dimerization state of NAMPT. Taken together,\u00a0the studies proposed will provide critical information regarding the biological mechanism of NAMPT.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Investigator:\u00a0Karen Almeida, Rhode Island College Scientific Theme:\u00a0Cancer Abstract:\u00a0NAD+ is essential for life and therefore must be strictly monitored. NAD+ is widely used as the cofactor in\u00a0cell energy production and metabolism by providing high-energy electrons required for oxidation\/reduction\u00a0reactions. However, NAD+ concentration is diminished by its use as a substrate for enzymes such as poly\u00a0(ADP-ribose) polymerases (PARPs) [&hellip;]<\/p>\n","protected":false},"author":1036,"featured_media":0,"parent":10206,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"page-twocol.php","meta":{"_acf_changed":false,"footnotes":"","_links_to":"","_links_to_target":""},"class_list":["post-4869","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/pages\/4869","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/users\/1036"}],"replies":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/comments?post=4869"}],"version-history":[{"count":0,"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/pages\/4869\/revisions"}],"up":[{"embeddable":true,"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/pages\/10206"}],"wp:attachment":[{"href":"https:\/\/web.uri.edu\/riinbre\/wp-json\/wp\/v2\/media?parent=4869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}