dMi-2 and ISWI chromatin remodelling factors have distinct nucleosome binding and mobilization properties.
Mi-2 and ISWI, two members of the Snf2 superfamily of ATPases, reside in separate ATP-dependent chromatin remodelling complexes. These complexes differ in their biochemical properties and are believed to perform distinct functions in the cell. We have compared the remodelling activity of recombinant Drosophila Mi-2 (dMi-2) with that of recombinant ISWI. Both proteins are nucleosome-stimulated ATPases and promote nucleosome mobilization. However, dMi-2 and ISWI differ in their interaction with nucleosome core particles, in their substrate requirements and in the direction of nucleosome mobilization. We have used antibodies to immobilize a complex containing dMi-2 and the dRPD3 histone deacetylase from Drosophila embryo extracts. This complex shares the nucleosome-stimulated ATPase and nucleosome mobilization properties of recombinant dMi-2, demonstrating that these activities are maintained in a physiological context. Its functional properties distinguish dMi-2 from both SWI2/SNF2 and ISWI, defining a new family of ATP-dependent remodelling machines.
Brehm
A
A
Adolf-Butenandt-Institut, Molekularbiologie, Ludwig-Maximilians-Universität, Schillerstrasse 44, 80336 München, Germany.
Längst
G
G
Kehle
J
J
Clapier
C R
CR
Imhof
A
A
Eberharter
A
A
Müller
J
J
Becker
P B
PB
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D001324:Autoantigens / Q000737:chemistry / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000737:chemistry / Q000378:metabolism*; D002467:Cell Nucleus / Q000378:metabolism; D002843:Chromatin / Q000737:chemistry* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D004330:Drosophila; D029721:Drosophila Proteins; D004625:Embryo, Nonmammalian / Q000737:chemistry; D004789:Enzyme Activation; D006657:Histones / Q000737:chemistry; D009707:Nucleosomes / Q000201:enzymology* / Q000378:metabolism; D011099:Polyglutamic Acid / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012965:Sodium Chloride / Q000378:metabolism; D019809:Streptavidin / Q000378:metabolism; D014157:Transcription Factors / Q000737:chemistry / Q000378:metabolism*
D001324:Autoantigens; D002352:Carrier Proteins; D002843:Chromatin; D029721:Drosophila Proteins; D006657:Histones; C086468:ISWI protein; C116095:Mi-2 protein, Drosophila; D009707:Nucleosomes; D011994:Recombinant Proteins; D014157:Transcription Factors; D011099:Polyglutamic Acid; D012965:Sodium Chloride; D019809:Streptavidin; D000251:Adenosine Triphosphatases