Prothymosin alpha is a chromatin-remodelling protein in mammalian cells.
Prothymosin alpha (ProTalpha) is an abundant mammalian acidic nuclear protein whose expression is related to cell proliferation. Here we report that in HL-60 cells overexpressing ProTalpha, the accessibility of micrococcal nuclease to chromatin is strongly increased. In the DNA ladder generated by the nuclease activity, the sizes of the mononucleosome (146 bp, the DNA fragment that is bound to the histone octamer) and its multimers correspond to nucleosomes lacking histone H1. The percentage of histone-H1-depleted chromatin (active chromatin) is also higher in the cells overexpressing ProTalpha. On the basis of these and previous findings, we propose a biological role for ProTalpha in the remodelling of chromatin fibres through its interaction with histone H1.
Gomez-Marquez
J
J
Departamento de Bioqu approximately ímica y Biolog approximately ía Molecular, Facultad de Biolog approximately ía, Universidad de Santiago de Compostela, 15706 Santiago de Compostela, Galicia, Spain. bnjgm@usc.es
Rodríguez
P
P
D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics; D018922:HL-60 Cells; D006657:Histones / Q000378:metabolism; D006801:Humans; D008836:Micrococcal Nuclease / Q000378:metabolism; D009707:Nucleosomes / Q000737:chemistry; D010957:Plasmids; D011498:Protein Precursors / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology; D013947:Thymosin / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology
D002843:Chromatin; D018076:DNA, Complementary; D006657:Histones; D009707:Nucleosomes; D011498:Protein Precursors; C040782:prothymosin alpha; D013947:Thymosin; D008836:Micrococcal Nuclease