pEg2 aurora-A kinase, histone H3 phosphorylation, and chromosome assembly in Xenopus egg extract.
In eukaryotes cell division is accompanied by phosphorylation of histone H3 at serine 10. In this work we have studied the kinase activity responsible for this histone H3 modification by using cell-free extracts prepared from Xenopus eggs. We have found that the Xenopus aurora-A kinase pEg2, immunoprecipitated from the extract, is able to phosphorylate specifically histone H3 at serine 10. The enzyme is incorporated into chromatin during in vitro chromosome assembly, and the kinetics of this incorporation parallels that of histone H3 phosphorylation. Recombinant pEg2 phosphorylates efficiently histone H3 at serine 10 in reconstituted nucleosomes and in sperm nuclei decondensed in heated extracts. These data identify pEg2 as a good candidate for mitotic histone H3 kinase. However, immunodepletion of pEg2 does not interfere with the chromosome assembly properties of the extract nor with the pattern of H3 phosphorylation, suggesting the existence of multiple kinases involved in this H3 modification in Xenopus eggs. This hypothesis is supported by in gel activity assay experiments using extracts from Saccharomyces cerevisiae.
Scrittori
L
L
Laboratoire de Biologie Moléculaire et Cellulaire de la Différenciation, INSERM U 309, Institut Albert Bonniot, Domaine de la Merci, 38706 La Tronche, Cedex, France.
Hans
F
F
Angelov
D
D
Charra
M
M
Prigent
C
C
Dimitrov
S
S
D000818:Animals; D064127:Aurora Kinases; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000378:metabolism; D002474:Cell-Free System; D002875:Chromosomes / Q000648:ultrastructure*; D005982:Glutathione Transferase / Q000378:metabolism; D006657:Histones / Q000378:metabolism*; D015151:Immunoblotting; D007700:Kinetics; D008856:Microscopy, Fluorescence; D009707:Nucleosomes / Q000378:metabolism; D010766:Phosphorylation; D011233:Precipitin Tests; D011494:Protein Kinases / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012694:Serine / Q000737:chemistry; D013997:Time Factors; D014981:Xenopus / Q000196:embryology*; D029867:Xenopus Proteins
D018797:Cell Cycle Proteins; D006657:Histones; D009707:Nucleosomes; D011994:Recombinant Proteins; D029867:Xenopus Proteins; D012694:Serine; D005982:Glutathione Transferase; D011494:Protein Kinases; C112134:AURKA protein, Xenopus; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases