Context-dependent RNA localization to nuclear speckles

Date: 8^th August, 2024 (Thursday)

Time: 4:30 - 5:30 pm (HKT)

Prof. Jingyi FEI

Department of Biochemistry and Molecular Biology

University of Chicago

Eukaryotic cells are highly compartmentalized. In addition to membrane-bound organelles, multivalent interactions among many RNA and protein species often drive the formation of membraneless organelles. Dynamic RNA localization to these phase-separated membraneless organelles profoundly impacts gene expression and other vital cellular activities, provides a key mechanism for stress response and adaptation, and has tight connections to human diseases. Nuclear speckles represent one type of such membraneless organelles in the nucleus of higher eukaryotes, enriched in snRNP species, splicing factors, polyadenylated RNAs and certain long noncoding RNAs. Nuclear speckles are implied to play roles in facilitating pre-mRNA splicing, an essential step during eukaryotic gene expression. However, direct evidence for involvement of nuclear speckles in mRNA metabolism remains a frontier challenge due to its compositional complexity. Using localized transcriptomic analysis, fluorescence microscopy and super-resolution imaging, our recent results demonstrate that the RNA substrates exhibit sequence context-dependent localization and organization in nuclear speckles. Through physically localizing and organizing RNA substrates, nuclear speckles functionally coordinating splicing activities during gene expression and regulation.