Chriz, a Chromodomain Protein Specific for the Interbands of Drosophila Melanogaster Polytene Chromosomes

Chromosoma. 2005 May;114(1):54-66. doi: 10.1007/s00412-005-0339-3. Epub 2005 Apr 9.

Abstract

Polytene interphase chromosomes are compacted into a series of bands and interbands reflecting their organization into independent chromosomal domains. In order to understand chromosomal organization, we set out to study the role of proteins that are selective for interbands. Here we describe the Drosophila melanogaster chromodomain protein Chriz that is coimmunoprecipitated with the zinc finger protein Z4. Both proteins colocalize exclusively to the interbands on Drosophila polytene chromosomes. Like Z4, Chriz is ubiquitously expressed throughout development and is associated with chromatin in all interphase nuclei. Following dissociation from chromatin, early in mitosis Chriz binds to the centrosomes and to the mitotic spindle. Newly induced amorphic Chriz alleles are early lethal, and ubiquitous overexpression of Chriz is lethal as well. Available Chriz hypomorphs which survive until pupal stage have a normal chromosomal phenotype. Reducing Z4 protein does not affect Chriz binding to polytene chromosomes and vice versa. Z4 is still chromosomally bound when Chriz protein is depleted by RNA interference.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alleles
  • Amino Acid Sequence
  • Animals
  • Animals, Genetically Modified
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism
  • Centrosome / metabolism
  • Chromatin / genetics
  • Chromatin / metabolism
  • Chromosomes / genetics
  • Chromosomes / metabolism*
  • Chromosomes / ultrastructure
  • Drosophila Proteins / antagonists & inhibitors
  • Drosophila Proteins / genetics
  • Drosophila Proteins / metabolism*
  • Drosophila melanogaster / cytology
  • Drosophila melanogaster / genetics*
  • Drosophila melanogaster / metabolism*
  • Female
  • Gene Expression Regulation, Developmental*
  • Immunoprecipitation
  • Interphase / genetics
  • Male
  • Mitosis
  • Molecular Sequence Data
  • Phenotype
  • RNA Interference
  • Sequence Homology, Amino Acid
  • Spindle Apparatus
  • Zinc Fingers / genetics*

Substances

  • Chromatin
  • Drosophila Proteins