A novel membrane-shaping protein important for mitochondrial ultrastructure found in the University of Helsinki

The protein is a critical organiser of the mitochondrial inner membrane and the finding sheds light on how the mitochondrial functional domains are compartmentalised.

Researchers in the University of Helsinki have discovered a novel membrane-shaping protein in the inner mitochondrial membrane. The protein FAM92A1 belongs to the BAR domain protein family, the largest and most diverse group of membrane-shaping proteins. Losing FAM92A1 created profound changes to mitochondrial membrane morphology and dynamics.

"The mitochondrial inner membrane is highly folded into specific invaginations called cristae which are essential for the production of ATP by oxidative phosphorylation. The structure and shape of cristae are critical for mitochondrial function. However, biogenesis of these important membrane invaginations and the underlying mechanisms are largely unknown," explains researcher Hongxia Zhao from the Institute of Biotechnology.

FAM92A1 resides in the mitochondrial inner membrane. It possesses membrane-remodelling activity that is crucial for the formation of mitochondrial membrane invaginations. Loss of FAM92A1 caused a drastic disruption of the mitochondrial membrane organization and impaired mitochondrial function.

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Liang Wang, Ziyi Yan, Helena Vihinen, Ove Eriksson, Weihuan Wang, Rabah Soliymani, Yao Lu, Yaxin Xue, Eija Jokitalo, Jing Li, Hongxia Zhao. FAM92A1 is a BAR domain protein required for mitochondrial ultrastructure and function. Journal of Cell Biology, DOI: 10.1083/jcb.201806191