Nuclear-mitochondrial interactions in somatic cell senescence in budding tunicates

2014 Fiscal Year Final Research Report

• Project/Area Number: 25650081
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Developmental biology
• Research Institution: Kochi University
• Principal Investigator: KAWAMURA Kaz 高知大学, 自然科学系, 教授 (30136361)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: ホヤ / 出芽 / 加齢 / ミトコンドリア / TFAM / Prohibitin 2 / ヒストンメチル化

Outline of Final Research Achievements

In the budding tunicate, Polyandrocarpa misakiensis, mitochondrial respiratory genes are repeatedly activated and inactivated in relation to budding and zooidal senescence. In this research project, it was examined how and to what extent 2 nuclear genes, mitochondrial transcription factor a (PmTFAM) and prohibitin 2 (PmPHN2), were involved in gene activation of mitochondrial cytochrome c oxidase subunit 1 (PmCOX1). Both PmTFAM and PmPHN2 were most abundantly expressed during budding stages and attenuated during ageing. An endogenous humoral factor, TC14-3, regulated PmTFAM and PmPHN2 gene expression via histone methylation and PmPHN2 was also influenced by histone acetylation. RNAi of PmTFAM caused PmCOX1 downregulation, and the transfection of PmTFAM mRNA upregulated PmCOX1 expression. These results strongly suggest that PmTFAM and PmPHN2 mediate the nuclear control of mitochondrial genes through histone modification.

Free Research Field

動物発生学