PROSITE documentation PDOC50219
Citron homology (CNH) domain profile


Based on sequence similarities a domain of homology has been identified near the N- or C-terminal end of the following proteins [1,2,3]:

  • Citron Rho-interacting kinase (CRIK). It interacts with the GTP-bound forms of the small GTPases Rho and Rac, but not with Cdc42.
  • Myotonic dystrophy kinase-related Cdc42-binding kinase (MRCKα). This serine/threonine kinase interacts with the GTP-bound form of the small GTPase Cdc42 and to a lesser extent with that of Rac.
  • NCK Interacting Kinase (NIK), a serine/threonine protein kinase.
  • Yeast ROM-1 and ROM-2. These proteins are GDP/GTP exchange proteins (GEPs) for the small GTP binding protein Rho1.
  • Eukaryotic Vam6/Vps39 protein. It may function as a tethering/docking factor specifically involved in lysosome fusion.

Little is known about the function of the CNH domain, although it has been proposed to regulate kinase activity and to mediate binding to the GTP-bound forms of Rac and Rho. The CNH domain is required for association with lysosomes and overexpression-induced lysosome clustering and fusion. It could interact with a docking protein or with lipids on the lysosomal membrane [3].

The profile we developed covers the entire CNH domain.

Last update:

September 2009 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

CNH, PS50219; Citron homology (CNH) domain profile  (MATRIX)


1AuthorsSu Y.-C. Han J. Xu S. Cobb M. Skolnik E.Y.
TitleNIK is a new Ste20-related kinase that binds NCK and MEKK1 and activates the SAPK/JNK cascade via a conserved regulatory domain.
SourceEMBO J. 16:1279-1290(1997).
PubMed ID9135144

2AuthorsChen X.-Q. Tan I. Leung T. Lim L.
TitleThe myotonic dystrophy kinase-related Cdc42-binding kinase is involved in the regulation of neurite outgrowth in PC12 cells.
SourceJ. Biol. Chem. 274:19901-19905(1999).
PubMed ID10391936

3AuthorsCaplan S. Hartnell L.M. Aguilar R.C. Naslavsky N. Bonifacino J.S.
TitleHuman Vam6p promotes lysosome clustering and fusion in vivo.
SourceJ. Cell Biol. 154:109-122(2001).
PubMed ID11448994

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