H2020Индивидуална стипендия2021–2023

StructuRNP · Cryo-EM structural analysis of small nuclear ribonucleoprotein particles (snRNP) biogenesis

„Хоризонт 2020“ — Действия „Мария Склодовска-Кюри“

Период: 2021-10-01 → 2023-09-30
Финансиране от ЕС: 186 167 €
Участници: 1
Схема: MSCA-IF

Линиите свързват координатора с партньорите.

Накратко на български

Структурата и процесите на обновяване на частицата U5 snRNP, която действа като център при сглобяването на сплайсозомата в човешките клетки, се анализират чрез криоелектронна микроскопия. Разбирането на този механизъм помага за изясняване на причините за развитието на заболявания като амиотрофична латерална склероза.

Този кратък обзор е генериран от изкуствен интелект

Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.

Резултати накратко

Cryo-EM structural analysis of small nuclear ribonucleoprotein particles (snRNP) biogenesis

Pre-mRNA splicing is carried out by the dynamic and multi-megadalton spliceosome, which assembles anew on each intron from pre-formed small nuclear ribonucleoprotein particles (snRNPs; U1, U2, U4, U5, U6) and non-snRNP proteins. The U2-U6 snRNPs undergo major compositional and conformational changes throughout spliceosome assembly, activation, catalysis, and disassembly. Among these, the U5 snRNP undergoes particularly dramatic changes, while serving as the ~1 megadalton “heart” of the spliceosome around which pre-mRNA, U1, U2, U4, and U6 snRNPs, and non snRNP proteins organize for splicing. After spliceosome disassembly, the post splicing U5 snRNP is recycled into a ‘20S U5 snRNP’, which subsequently scaffolds the formation of the ~2 megadalton U4/U6.U5 tri-snRNP for the next round of splicing. While the molecular basis of pre-mRNA splicing has been extensively studied the structural mechanism of U5 snRNP biogenesis and recycling remained unknown. Impaired recycling and biogenesis of the spliceosomal components has been linked to a plethora of diseases, such as Lobular Neoplasia, Cardiofaciocutaneous Syndrome or Amyotrophic Lateral Sclerosis. Hence, our objective was to study the cryo-EM structure of native human U5 snRNP in its recycling state, to shed light on the functional aspects of the spliceosome recycling process that may also have implications to understand these diseases.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз

Цел на проекта

The spliceosome is a multi-megadalton enzyme that catalyses the excision of non-coding introns from nuclear pre-mRNA. It is assembled from five small nuclear ribonucleoprotein particles (snRNPs) and non-snRNP factors, while each snRNP contains a unique small nuclear RNA (snRNA, U1-U5) and is bound by the heptameric Sm-ring. Acquisition of the Sm-ring is a key quality control step in snRNP biogenesis, defects of which are linked with several human diseases. In humans, snRNP biogenesis requires at least 15 proteins, including the 9-subunit survival of motor neuron (SMN) complex. The SMN complex carries out the regulated and specific loading of the Sm ring onto snRNA. Recent studies have revealed the structure of several key proteins that play a role in snRNP assembly, however the complete structures of either the SMN complex alone or with interacting Sm ring and or the snRNP as a whole, are lacking and culminate to a big gap in our knowledge of the snRNP assembly. In this proposal, I will reconstitute key steps in snRNP biogenesis in humans and will determine their structures using cryo-electron microscopy and cross-linking mass spectrometry. I will study how the SMN complex specifically loads the Sm-ring onto U1 snRNA, as a model snRNP. Additionally, purification and structural analysis of endogenous SMN complex will reveal SMN complex stoichiometry and validate the in vitro work. The structures will reveal the interacting partners and the structural transitions within the assembled snRNP and will enable structure-guided biochemical and tissue culture validation of SMN complex function, while my background in protein biochemistry and human tissue culture makes me ideally suited to carry out this high-impact project. StructuRNP will provide first insights into the molecular events and choreography of the spliceosome, providing a leap in our understanding of spliceosome function and thus will have far reaching implications for RNA and spliceosome fields.

Оригинален текст от CORDIS (на английски).

Участници

FORSCHUNGSINSTITUT FUR MOLEKULARE PATHOLOGIE GESELLSCHAFT MBH · WienКоординаторАвстрия