Other: LIM Domain

Domain Binding and Function

The LIM domain was first identified in three developmentally regulated transcription factors Lin-1, Isl-1 and Mec-3. It consists of approximately 60 amino acids and has been identified in over 300 proteins from organisms ranging from yeast to humans. The LIM domain is a zincbinding, cysteine-rich motif consisting of two tandemly repeated zinc fingers. Unlike GATA-type zinc fingers, LIM domains do not seem to bind DNA but instead appear to mediate protein—protein interactions. Functionally, LIM domain—containing proteins have been implicated in a variety of biological processes including cell lineage specification, cytoskeletal organization and organ development. Some LIM domain—containing proteins appear to function solely as adapters to bring together other components into a complex (i.e., LMO and CRP) while other LIM domain containing proteins clearly have other functions conferred by additional functional domains such as the DNA binding homeodomain or a catalytic kinase domain. In addition, certain LIM domains have been observed to form dimers with other LIM domains. An overall consensus LIM domain binding site has not been defined. Factors that confer the specificity of LIM domain interactions remain to be determined.

Structure Reference

1. Konrat, R. et al. (1997) J. Biol. Chem. 272(18), 12001–12007.

Examples of Domain Proteins

Binding Examples

LIM Domain Proteins	Binding Partners	Domain Binding Sites
Enigma	Insulin receptor via third LIM domain of Enigma	Tyrosine-containing tight turn in Insulin Receptor
Enigma	Ret receptor via second LIM domain of Enigma	NKLY sequence near C-terminus of ret receptor.
PINCH	Integrin-linked kinase (ILK) via first LIM domain of PINCH	ANK repeat region of ILK
hCRP	hCRP via LIM domains	LIM domain homo-dimerization