Transcriptional regulators involved in nuclear histone modification and mitochondrial gene expression

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07078
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Developmental biology
• Research Institution: Kochi University
• Principal Investigator: Kawamura Kazuo 高知大学, その他部局等(名誉教授), 名誉教授 (30136361)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: ホヤ / ミトコンドリア / Tfam / YY1 / Sirtuin6 / プルダウンアッセイ / ゲルシフトアッセイ / 架橋法

Outline of Final Research Achievements

Aging accompanies the decrease in mitochondrial gene and respiratory activities. In the budding tunicate, Polyandrocarpa misakiensis, mitochondrial activities are repeatedly regulated during aging and budding cycles. This research project revealed first that mitochondrial transcription factor A (TFAM) acts on the D-loop of mitochondrial genome to facilitate the expression of downstream genes. Both the transcription factor, Yin-Yang-1 (YY1) and the transcriptional corepressor, Sirtuin 6 (SIRT6) are upregulated during zooidal aging. PmSirt6 mRNA, when introduced into buds together with PmYY1 mRNA, severely downregulated TFAM gene expression. Pull-down assays, gel shift assays, and cross-linking experiments indicated that YY1 recruited SIRT6 to the 5’ upstream region of TFAM gene to facilitate the deacetylation of histone H3K9. These results indicate that during normal tunicate aging, epigenetic histone modification causes the decrease of mitochondrial activity without genetic damage.

Free Research Field

発生生殖生物学