The ISWI chromatin-remodeling protein is required for gene expression and the maintenance of higher order chromatin structure in vivo.
Drosophila ISWI, a highly conserved member of the SWI2/SNF2 family of ATPases, is the catalytic subunit of three chromatin-remodeling complexes: NURF, CHRAC, and ACF. To clarify the biological functions of ISWI, we generated and characterized null and dominant-negative ISWI mutations. We found that ISWI mutations affect both cell viability and gene expression during Drosophila development. ISWI mutations also cause striking alterations in the structure of the male X chromosome. The ISWI protein does not colocalize with RNA Pol II on salivary gland polytene chromosomes, suggesting a possible role for ISWI in transcriptional repression. These findings reveal novel functions for the ISWI ATPase and underscore its importance in chromatin remodeling in vivo.
Deuring
R
R
Department of Biology, University of California, Santa Cruz 95064, USA.
Fanti
L
L
Armstrong
J A
JA
Sarte
M
M
Papoulas
O
O
Prestel
M
M
Daubresse
G
G
Verardo
M
M
Moseley
S L
SL
Berloco
M
M
Tsukiyama
T
T
Wu
C
C
Pimpinelli
S
S
Tamkun
J W
JW
D000107:Acetylation; D000251:Adenosine Triphosphatases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002470:Cell Survival; D002843:Chromatin / Q000648:ultrastructure*; D002875:Chromosomes / Q000648:ultrastructure*; D004268:DNA-Binding Proteins; D004330:Drosophila / Q000033:anatomy & histology / Q000196:embryology / Q000235:genetics; D029721:Drosophila Proteins; D022041:Euchromatin; D005260:Female; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D020043:Genes, Essential; D006570:Heterochromatin / Q000648:ultrastructure; D018398:Homeodomain Proteins / Q000302:isolation & purification / Q000378:metabolism; D008297:Male; D008938:Mitosis; D009154:Mutation; D010641:Phenotype; D014157:Transcription Factors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014960:X Chromosome / Q000648:ultrastructure*
D002843:Chromatin; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D022041:Euchromatin; D006570:Heterochromatin; D018398:Homeodomain Proteins; C086468:ISWI protein; D014157:Transcription Factors; C063460:Trl protein, Drosophila; D000251:Adenosine Triphosphatases