title: C. elegans PAT-9 is a nuclear zinc finger protein critical for the assembly of muscle attachments.
abstract: BACKGROUND
  Caenorhabditis elegans sarcomeres have been studied extensively utilizing both forward and reverse genetic techniques to provide insight into muscle development and the mechanisms behind muscle contraction. A previous genetic screen investigating early muscle development produced 13 independent mutant genes exhibiting a Pat (paralyzed and arrested elongation at the two-fold length of embryonic development) muscle phenotype. This study reports the identification and characterization of one of those genes, pat-9.
  
  
  RESULTS
  Positional cloning, reverse genetics, and plasmid rescue experiments were used to identify the predicted C. elegans gene T27B1.2 (recently named ztf-19) as the pat-9 gene. Analysis of pat-9 showed it is expressed early in development and within body wall muscle lineages, consistent with a role in muscle development and producing a Pat phenotype. However, unlike most of the other known Pat gene family members, which encode structural components of muscle attachment sites, PAT-9 is an exclusively nuclear protein. Analysis of the predicted PAT-9 amino acid sequence identified one putative nuclear localization domain and three C2H2 zinc finger domains. Both immunocytochemistry and PAT-9::GFP fusion expression confirm that PAT-9 is primarily a nuclear protein and chromatin immunoprecipitation (ChIP) experiments showed that PAT-9 is present on certain gene promoters.
  
  
  CONCLUSIONS
  We have shown that the T27B1.2 gene is pat-9. Considering the Pat-9 mutant phenotype shows severely disrupted muscle attachment sites despite PAT-9 being a nuclear zinc finger protein and not a structural component of muscle attachment sites, we propose that PAT-9 likely functions in the regulation of gene expression for some necessary structural or regulatory component(s) of the muscle attachment sites.
authors.affiliation: Department of Cell and Developmental Biology, University of Illinois at Urbana-Champaign, 601 S, Goodwin Ave, B107 Chemical and Life Sciences Laboratory, Urbana, IL, 61801, USA. pjones@bbri.org.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.forename: Takako I
authors.initials: TI
authors.lastname: Jones
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Bachmann
authors.forename: Mitchell
authors.initials: M
authors.lastname: Meghpara
authors.forename: Lauren
authors.initials: L
authors.lastname: Rogowski
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Williams
authors.forename: Peter L
authors.initials: PL
authors.lastname: Jones