Human histone chaperone nucleophosmin enhances acetylation-dependent chromatin transcription.
Histone chaperones are a group of proteins that aid in the dynamic chromatin organization during different cellular processes. Here, we report that the human histone chaperone nucleophosmin interacts with the core histones H3, H2B, and H4 but that this histone interaction is not sufficient to confer the chaperone activity. Significantly, nucleophosmin enhances the acetylation-dependent chromatin transcription and it becomes acetylated both in vitro and in vivo. Acetylation of nucleophosmin and the core histones was found to be essential for the enhancement of chromatin transcription. The acetylated NPM1 not only shows an increased affinity toward acetylated histones but also shows enhanced histone transfer ability. Presumably, nucleophosmin disrupts the nucleosomal structure in an acetylation-dependent manner, resulting in the transcriptional activation. These results establish nucleophosmin (NPM1) as a human histone chaperone that becomes acetylated, resulting in the enhancement of chromatin transcription.
Swaminathan
V
V
Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Center for Advanced Scientific Research, Jakkur, Bangalore, India.
Kishore
A Hari
AH
Febitha
K K
KK
Kundu
Tapas K
TK
D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D002843:Chromatin / Q000235:genetics*; D005786:Gene Expression Regulation; D006367:HeLa Cells; D006657:Histones / Q000378:metabolism*; D006801:Humans; D018832:Molecular Chaperones / Q000378:metabolism*; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000090243:Nucleophosmin; D011485:Protein Binding; D014158:Transcription, Genetic / Q000235:genetics*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D014982:Xenopus laevis
D002843:Chromatin; D006657:Histones; D018832:Molecular Chaperones; C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D016159:Tumor Suppressor Protein p53; D000090243:Nucleophosmin