2024/11/05 by Dahyana Arias Escayola, Chuyue Zhang, Emily Nischwitz +6 · 1 voice
Biochemistry, Genetics and Molecular Biology · #RNA Research and Splicing #RNA and protein synthesis mechanisms #RNA modifications and cancer
paper · pdf · doi:10.1083/jcb.202305081
openalex publication_date 2024/11/05 · openalex created_date 2024/11/27 · openalex updated_date 2026/08/01
The cell nucleus contains distinct biomolecular condensates that form at specific genetic loci, organize chromosomes in 3D space, and regulate RNA processing. Among these, Cajal bodies (CBs) require key "scaffolding" proteins for their assembly, which is not fully understood. Here, we employ proximity biotinylation, mass spectrometry, and functional screening to comprehensively identify and test the functions of CB components. We document 144 protein interactors of coilin, of which 70 were newly detected, and establish 25 players needed for CB assembly and/or maintenance. Surprisingly, the depletion of nine coilin interactors-mostly constituents of the 60S ribosome (RPLs)-increased CB number and caused subdomains defined by coilin and the survival motor neuron protein (SMN) to merge. These phenotypes were traceable to altered nuclear levels of dimethylarginine. Our data implicate RPL24 and other players in the regulation of CBs by modulating posttranslational modifications. Moreover, the prevalence of transcription factors among the identified components highlights roles for gene activity in CB assembly and nuclear positioning.