Zizimin2: a novel, DOCK180-related Cdc42 guanine nucleotide exchange factor expressed predominantly in lymphocytes

FEBS Lett. 2005 Feb 14;579(5):1039-46. doi: 10.1016/j.febslet.2005.01.006. Epub 2005 Jan 13.


A novel superfamily of guanine nucleotide exchange factors for Rho GTPases includes DOCK180 and zizimin1. The zizimin subfamily includes three genes of which only zizimin1 has been cloned. We report here the cloning of zizimin2, identified in a screen for genes enriched in germinal center B cells. Zizimin2 and zizimin1 have similar primary structures and both proteins bound and activated Cdc42 but not the Cdc42-related proteins TC10 or TCL. Their tissue distributions are distinct, however, with zizimin2 expressed predominantly in lymphocytes and an opposite pattern for zizimin1. Zizimin3 was also analyzed and showed distinct GTPase specificity and tissue distribution.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Cloning, Molecular
  • Enzyme Activation
  • Gene Expression Profiling
  • Guanine Nucleotide Exchange Factors / chemistry
  • Guanine Nucleotide Exchange Factors / genetics
  • Guanine Nucleotide Exchange Factors / metabolism*
  • Lymphocytes / chemistry
  • Lymphocytes / metabolism*
  • Mice
  • Molecular Sequence Data
  • Protein Binding
  • Protein Isoforms / chemistry
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Substrate Specificity
  • cdc42 GTP-Binding Protein / chemistry
  • cdc42 GTP-Binding Protein / genetics
  • cdc42 GTP-Binding Protein / metabolism*
  • rac GTP-Binding Proteins / metabolism*


  • Dock11 protein, mouse
  • Guanine Nucleotide Exchange Factors
  • Protein Isoforms
  • cdc42 GTP-Binding Protein
  • rac GTP-Binding Proteins

Associated data

  • GENBANK/AB116935