Nap1 and Kap114 co-chaperone H2A-H2B and facilitate targeted histone release in the nucleus.
| Autor: | Fung HYJ; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA., Jiou J; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA., Niesman AB; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA.; Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, USA., Bernardes NE; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA., Chook YM; Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, USA. |
|---|---|
| Jazyk: | angličtina |
| Zdroj: | The Journal of cell biology [J Cell Biol] 2025 Jan 06; Vol. 224 (1). Date of Electronic Publication: 2024 Nov 27. |
| DOI: | 10.1083/jcb.202408193 |
| Abstrakt: | Core histones, synthesized and processed in the cytoplasm, must be chaperoned as they are transported into the nucleus for nucleosome assembly. The importin Kap114 transports H2A-H2B into the yeast nucleus, where RanGTP facilitates histone release. Kap114 and H2A-H2B also bind the histone chaperone Nap1, but how Nap1 and Kap114 cooperate in transport and nucleosome assembly remains unclear. Here, biochemical and structural analyses show that Kap114, H2A-H2B, and a Nap1 dimer (Nap12) associate in the absence and presence of RanGTP to form equimolar complexes. A previous study had shown that RanGTP reduces Kap114's ability to chaperone H2A-H2B, but a new cryo-EM structure of the Nap12•H2A-H2B•Kap114•RanGTP complex explains how both Kap114 and Nap12 interact with H2A-H2B, restoring its chaperoning within the assembly while effectively depositing it into nucleosomes. Together, our results suggest that Kap114 and Nap12 provide a sheltered path that facilitates the transfer of H2A-H2B from Kap114 to Nap12, ultimately directing its specific deposition into nucleosomes. (© 2024 Fung et al.) |
| Databáze: | MEDLINE |
| Externí odkaz: |
|