Association of chromatin proteins high mobility group box (HMGB) 1 and HMGB2 with mitotic chromosomes.
High mobility group box (HMGB) 1 and 2 are two abundant nonhistone nuclear proteins that have been found in association with chromatin. Previous studies based on immunofluorescence analysis indicated that HMGB1 dissociates from chromosomes during mitosis. In the present work, HMGB1 and 2 subcellular localization was reinvestigated in living cells by using enhanced green fluorescent protein- and Discosome sp. red fluorescent protein-tagged proteins. Contrary to previous reports, HMGB1 and 2 were shown to be present under two forms in mitotic cells, i.e., free and associated with the condensed chromatin, which rapidly exchange. A detailed analysis of HMGB2 interaction with mitotic chromosomes indicated that two sites encompassing HMG-box A and B are responsible for binding. Importantly, this interaction was rapidly inactivated when cells were permeabilized or exposed to chemical fixatives that are widely used in immunodetection techniques. A comparable behavior was also observed for two proteins of the HMG-nucleosome binding (HMGN) group, namely, HMGN1 and HMGN2.
Pallier
Coralie
C
Unité de Virologie, Service de Bactériologie-Virologie, Hôpital de Bicêtre, Assistance Publique/Hôpitaux de Paris, 94275 Le Kremlin Bicêtre, France.
Scaffidi
Paola
P
Chopineau-Proust
Stéphanie
S
Agresti
Alessandra
A
Nordmann
Patrice
P
Bianchi
Marco E
ME
Marechal
Vincent
V
D016475:3T3 Cells; D000818:Animals; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism* / Q000502:physiology; D002875:Chromosomes / Q000378:metabolism*; D049452:Green Fluorescent Proteins; D024243:HMGB1 Protein / Q000378:metabolism*; D024261:HMGB2 Protein / Q000378:metabolism*; D024001:HMGN Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008164:Luminescent Proteins; D051379:Mice; D008938:Mitosis / Q000502:physiology; D010539:Permeability; D011994:Recombinant Proteins; D000097573:Red Fluorescent Protein
D002843:Chromatin; D049452:Green Fluorescent Proteins; D024243:HMGB1 Protein; D024261:HMGB2 Protein; D024001:HMGN Proteins; D008164:Luminescent Proteins; D011994:Recombinant Proteins; D000097573:Red Fluorescent Protein