The Cajal body (CB) is a conserved non-membrane nuclear structure where several steps of small nuclear RNP particle (snRNP) biogenesis take place. It has been proposed that CB formation follows a liquid-liquid phase separation model, but this hypothesis has never been rigorously tested. Here, we applied live-cell imaging to show that the key CB assembly factor coilin is mobile within the CB, and we revealed a diffusion barrier that limits the coilin exchange between CBs and the nucleoplasm. We generated single aa mutations and demonstrated that RNA-dependent coilin oligomerization and coilin interaction with snRNP are essential for CB formation and maintenance. We applied these data to formulate a mathematical model that links the movement of coilin within the nucleoplasm, CB, and across the boundary with its oligomerization and snRNP binding. Our results illustrate CB as a structure dynamically responding to snRNP assembly and recycling.

• MeSH
• Cajalova tělíska * metabolismus   genetika   MeSH
• HeLa buňky MeSH
• jaderné proteiny * metabolismus   genetika   MeSH
• lidé MeSH
• multimerizace proteinu MeSH
• mutace MeSH
• ribonukleoproteiny malé jaderné * metabolismus   genetika   MeSH
• spliceozomy * metabolismus   genetika   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• jaderné proteiny * MeSH
• p80-coilin MeSH Prohlížeč
• ribonukleoproteiny malé jaderné * MeSH

The nucleus of higher eukaryotes contains a number of structures that concentrate specific biomolecules and play distinct roles in nuclear metabolism. In recent years, the molecular mechanisms controlling their formation have been intensively studied. In this brief review, I focus on coilin and Cajal bodies. Coilin is a key scaffolding protein of Cajal bodies that is evolutionarily conserved in metazoans. Cajal bodies are thought to be one of the archetypal nuclear structures involved in the metabolism of several short non-coding nuclear RNAs. Yet surprisingly little is known about the structure and function of coilin, and a comprehensive model to explain the origin of Cajal bodies is also lacking. Here, I summarize recent results on Cajal bodies and coilin and discuss them in the context of the last three decades of research in this field.

• Klíčová slova
• Cajal bodies, coilin, snRNA, snRNP, snoRNA, telomerase RNA,
• MeSH
• buněčné jádro * MeSH
• Cajalova tělíska * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH