GBPL3 is a novel component of the nuclear pore complex and functionally connects the nuclear basket with the nucleoskeleton in plants

ABSTRACT: The nuclear basket (NB) is an essential structure of the nuclear pore complex (NPC). It serves as a dynamic and multi-functional platform that participates in various critical nuclear processes, including cargo transport, molecular docking, and gene expression regulation. However, the compositional and functional mechanisms are not completely understood, particularly in plants. Here, we identified a guanylate-binding protein (GBP)-like GTPase (GBPL3) as a novel NPC basket component in Arabidopsis. Using fluorescence and immunoelectron microscopy, we found that GBPL3 is enriched in the nuclear rim and localizes to the nuclear pore. Proximity labeling proteomics and protein-protein interaction assays revealed that GBPL3 is predominantly distributed at the NPC basket and physically associated with NB nucleoporins as well as many chromatin remodelers, transcription apparatus, and regulators, and the RNA splicing and processing machinery, suggesting a conserved function of the nuclear basket in transcription regulation as reported in yeasts and animals. Moreover, we found that GBPL3 physically interacts with the nucleoskeleton via its disordered coiled-coil regions. Simultaneous loss of GBPL3 with any one of all the four Arabidopsis nucleoskeleton genes CRWNs led to distinct development- and stress-related phenotypes, ranging from seedling lethality to leaf lesions, concomitant aberrant transcription of stress-related genes. Our results indicate that GBPL3 is a bona fide component of the plant NPC and physically and functionally connects the nuclear basket with different components of the nucleoskeleton, which is required for the coordination of plant development and stress responses.

INSTRUMENT(S): LTQ Orbitrap

ORGANISM(S): Arabidopsis Thaliana (mouse-ear Cress)

TISSUE(S): Plant Cell, Seedling

SUBMITTER: Yu Tang  

LAB HEAD: Yangnan Gu

PROVIDER: PXD032906 | Pride | 2022-08-25

REPOSITORIES: Pride