PT  - JOURNAL ARTICLE
AU  - Pierre Bensidoun
AU  - Taylor Reiter
AU  - Ben Montpetit
AU  - Daniel Zenklusen
AU  - Marlene Oeffinger
TI  - Nuclear mRNA metabolism drives selective basket assembly on a subset of nuclear pores in budding yeast
AID  - 10.1101/2021.11.07.467636
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.11.07.467636
4099  - http://biorxiv.org/content/early/2021/11/08/2021.11.07.467636.short
4100  - http://biorxiv.org/content/early/2021/11/08/2021.11.07.467636.full
AB  - To determine which transcripts should reach the cytoplasm for translation, eukaryotic cells have established mechanisms to regulate selective mRNA export through the nuclear pore complex (NPC). The nuclear basket, a substructure of the NPC protruding into the nucleoplasm, is thought to function as a stable platform where mRNA-protein complexes (mRNPs) are rearranged and undergo quality control (QC) prior to export, ensuring that only mature mRNAs reach the cytoplasm. Here, we use proteomic, genetic, live-cell, and single-molecule resolution microscopy approaches in budding yeast to demonstrate that baskets assemble only on a subset of NPCs and that basket formation is dependent on RNA polymerase II (Pol II) transcription and subsequent mRNP processing. Specifically, we observe that the cleavage and polyadenylation machinery, the poly(A)-binding protein Pab1, and pre-mRNA-leakage factor Pml39 are required for basket assembly. We further show that while all nuclear pores can bind Mlp1, baskets assemble only on a subset of nucleoplasmic NPCs, and these basket-containing pores associate a distinct protein and RNA interactome. Taken together, our data points towards nuclear pore heterogeneity and an RNA-dependent mechanism for functionalization of nuclear pores in budding yeast through nuclear basket assembly.Competing Interest StatementThe authors have declared no competing interest.