Identification of Coilin Interactors Reveals Coordinated Control of Cajal Body Number and Structure

Overview

Journal J Cell Biol

Specialty Cell Biology

Date 2024 Nov 27

PMID 39602297

Authors

Dahyana Arias Escayola

Chuyue Zhang

Emily Nischwitz

Leonard Scharfen

Kerstin Dorner

Korinna Straube

Ulrike Kutay

Falk Butter

Karla M Neugebauer

Affiliations

Soon will be listed here.

Abstract

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.

Citing Articles

Regulation of Cajal bodies: Unexpected connection to 60S ribosomes.

Courvan E, Parker R J Cell Biol. 2025; 224(2.

PMID: 39786343 PMC: 11716109. DOI: 10.1083/jcb.202501009.

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