Dataset Information

Evidence for the nuclear import of monomeric histones H3.1 & H4

ABSTRACT: We present here evidence that histones H3.1 and H4 can be imported into the nucleus as monomers in human cells. Using a tether-and-release system to study the cytosolic phase and import dynamics of newly synthesised histones, we find that H3.1 and H4 can be maintained as stable monomers in the cytosol in a tethered state. Cytosolically tethered histones are bound tightly to Importin- proteins (predominantly IPO4), but not to the histone specific chaperones NASP, ASF1a, RbAp46 (RBBP7) or HAT1, which reside in the nucleus in interphase cells. Release of monomeric histones from their cytosolic tether results in rapid nuclear translocation, dissociation with IPO4 and incorporation into chromatin at sites of replication. Quantitative analysis of histones bound to individual chaperones under steady-state conditions reveals an excess of H3 specifically associated with sNASP, suggesting that NASP can maintain a soluble, monomeric pool of H3 within the nucleus and may act as a nuclear receptor for newly imported histone. In summary, we propose that histones H3 and H4 are rapidly imported as monomeric units, forming heterodimers in the nucleus rather than the cytosol, with sNASP acting as a potential nuclear receptor for monomeric histone H3.

INSTRUMENT(S): Orbitrap Fusion

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Hela Cell

SUBMITTER: Juan Ramon Hernandez-Fernaud

LAB HEAD: Andrew Bowman

PROVIDER: PXD009915 | Pride | 2018-09-10

REPOSITORIES: Pride

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Dataset's files

Source:

			Action	DRS
	MaxQuant_results.zip	Other
	OT_180327_101_MS18-067_B_L1-1.raw	Raw
	OT_180327_101_MS18-067_B_L1-2.raw	Raw
	OT_180327_101_MS18-067_B_L2-1.raw	Raw
	OT_180327_101_MS18-067_B_L2-2.raw	Raw

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Evidence for the nuclear import of histones H3.1 and H4 as monomers.

Apta-Smith Michael James MJ Hernandez-Fernaud Juan Ramon JR Bowman Andrew James AJ

The EMBO journal 20180903 19

Newly synthesised histones are thought to dimerise in the cytosol and undergo nuclear import in complex with histone chaperones. Here, we provide evidence that human H3.1 and H4 are imported into the nucleus as monomers. Using a tether-and-release system to study the import dynamics of newly synthesised histones, we find that cytosolic H3.1 and H4 can be maintained as stable monomeric units. Cytosolically tethered histones are bound to importin-alpha proteins (predominantly IPO4), but not to his ...[more]

PMID: 30177573

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