Speaker: Alexey Amunts, associate professor at Stockholm University, Sweden

Date: January 11, 2024

Time: 9:30-11:30

Location: E119, Huagangyuan Building, Qingdao Campus, Shandong University

Tencent Meeting: 688 588 8863

Sponsor: Frontiers Science Center for Nonlinear Expectations, Shandong University; Research Centre for Mathematics and Interdisciplinary Sciences Centre, Shandong University; Sino-Russian Mathematics Center in Qingdao

Abstract:

The mitoribosome translates specific mitochondrial mRNAs and regulates energy production that is a signature of all eukaryotic life forms. We present cryo-EM analyses of its assembly intermediates, mRNA binding process, and nascent polypeptide delivery to the membrane. To study the assembly mechanism, we determined a series of the small mitoribosomal subunit intermediates in complex with auxiliary factorsthat explain how action of step-specific factors establishes the catalytic mitoribosome. A delivery of mRNA is then performed by a helical repeat factor LRPPRC that forms a stable complex with a small binding partner SLIRP.In mammals,LRPPRC stabilises mRNAs co-transcriptionally, thus it links the entire gene expression system. Through the translation cycle, a nascent polypeptide is delivered to the mitochondrial inner membrane, and we report the mitoribosome structure bound to the insertase OXA1, which elucidates the basis forprotein synthesis couplingto membrane delivery. Together with experimental identification of functionally non-protein cofactors and specific rRNA and protein modifications, the data illuminate principal components responsible for the translation of genetic material in mitochondria.

Bio:

Alexey Amunts earned his PhD from Tel Aviv University for work on a plant Photosystem I, and did a postdoc at the Laboratory of Molecular Biology in Cambridge on cryo-EM studies of a mitoribosome. In 2016, he established an independent group at Stockholm University focusing on mechanisms of mitochondrial translation and bioenergetics, and since 2020 he is an Associate Professor. The group studies mitochondrial protein synthesis and energy production at the molecular and cellular level, and examines how these fundamental processes are affected by natural selection and disease. He is currently a visiting Professor at Westlake University.

For more information, please visit:

https://www.view.sdu.edu.cn/info/1020/187066.htm