Histone methyltransferase PRDM8 regulates mouse testis steroidogenesis

Area of Science:

• Epigenetics and Gene Regulation
• Molecular Biology
• Chromatin Biology

Background:

• PRDM proteins are chromatin modifiers with SET domains, influencing cellular processes like transcription.
• Histone methyltransferases (HMTases) play crucial roles in regulating gene expression through chromatin modification.

Purpose of the Study:

• To identify and characterize novel proteins with HMTase activity, specifically focusing on those containing the SET domain.
• To investigate the function and regulatory role of the identified PRDM8 protein in cellular processes and development.

Main Methods:

• Bioinformatic analysis to identify SET domain-containing proteins.
• In vitro HMTase assays and immunoblot analysis to determine PRDM8's enzymatic activity and specificity.
• Analysis of PRDM8 recruitment to promoters and its effect on gene expression, including HDAC involvement.
• Tissue blot analysis to identify PRDM8 transcript distribution in adult mouse tissues.

Main Results:

• PRDM8, a novel double zinc-finger domain-containing protein with HMTase activity, was identified.
• PRDM8 specifically methylates histone H3K9, indicating transcriptional repression activity.
• PRDM8 directly recruits to promoters to mediate transcriptional repression, independent of HDAC.
• PRDM8 transcripts are present in adult mouse brain and testis.
• PRDM8 represses the expression of steroidogenic markers (p450c17c and LHR) in vitro.

Conclusions:

• PRDM8 functions as a transcriptional repressor through H3K9 methylation.
• PRDM8 plays a significant regulatory role in mouse testis development by controlling key steroidogenic gene expression.