We identified a basic helix-loop-helix transcription factor, SHARP-2 (also referred to as the DEC1, Stra13, and BHLHB2), as an insulin-inducible transcription factor in the rat liver fed with a high-carbohydrate diet. Overexpression of SHARP-2 in cultured cells leads to a decrease in the levels of phosphoenolpyruvate carboxykinase mRNA that is a gluconeogenic enzyme gene involving in an elevation of blood glucose level. Thus, we suppose that SHARP-2 is an important transcription factor in the insulin signaling pathway.<\/p>\n
We are studying on a screening of the SHARP-2-regulatable genes, an analysis of transcriptional regulatory mechanisms by SHARP-2, and an analysis of transcriptional stimulatory mechanisms of the rat SHARP-2 gene by insulin. As the SHARP-2 is an insulin-inducible transcription factor, an increase of SHARP-2 expression by a bioactive material(s) without insulin is useful for patients of the type II diabetes mellitus (T2DM). We are also doing a search of such a material including food composition.<\/p>\n
We first identified human ZHX1, ZHX2, and ZHX3 transcriptional repressors as members of the zinc-fingers and homeoboxes (ZHX) protein family. These proteins form homo- and hetero-dimers with each other. It has been reported that the A subunit of nuclear factor-Y (NF-YA) activates transcription of the cell growth-related genes. The ZHX family proteins interact with the NF-YA and repress NF-Y-dependent gene transcription.<\/p>\n
We are studying on a relationship between cell growth and biological activities of the ZHX family proteins in addition to mechanisms of transcriptional repression by the ZHX family proteins.<\/p>\n
In a collaboration with Dr. Haruhiko Osawa (University of Ehime), we reported that the G\/G genotype of a resistin single-nucleotide polymorphism at -420 increases Japanese T2DM susceptibility by inducing promoter activity through specific binding of Sp1\/3. We are doing a screening and characterization of the T2DM candidate genes.<\/p>\n","protected":false},"excerpt":{"rendered":"
1) Analysis of regulatory mechanisms of gene transcription by nutrients and hormones. We identified a basic helix-loop-helix transcription factor, SHARP-2 (also referred to as the DEC1, Stra13, and BHLHB2), as an insulin-inducible transcription factor in the rat liver fed with a high-carbohydrate diet. Overexpression of SHARP-2 in cultured cells leads to a decrease in the levels of phosphoenolpyruvate carboxykinase mRNA that is a gluconeogenic enzyme gene involving in an elevation of blood glucose level. Thus, we suppose that SHARP-2 is an important transcription factor in the insulin signaling pathway. We are studying on a screening of the SHARP-2-regulatable genes, an analysis of transcriptional regulatory mechanisms by SHARP-2, and an analysis … Continue reading Research Theme<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_locale":"en_US","_original_post":"42","footnotes":""},"class_list":["post-47","page","type-page","status-publish","hentry","en-US"],"_links":{"self":[{"href":"http:\/\/professors.matsumoto-u.ac.jp\/yamada\/index.php?rest_route=\/wp\/v2\/pages\/47","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/professors.matsumoto-u.ac.jp\/yamada\/index.php?rest_route=\/wp\/v2\/pages"}],"about":[{"href":"http:\/\/professors.matsumoto-u.ac.jp\/yamada\/index.php?rest_route=\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"http:\/\/professors.matsumoto-u.ac.jp\/yamada\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/professors.matsumoto-u.ac.jp\/yamada\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=47"}],"version-history":[{"count":0,"href":"http:\/\/professors.matsumoto-u.ac.jp\/yamada\/index.php?rest_route=\/wp\/v2\/pages\/47\/revisions"}],"wp:attachment":[{"href":"http:\/\/professors.matsumoto-u.ac.jp\/yamada\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=47"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}