LIM-group homeodomain-containing proteins constitute a major class of transcriptional regulators. A subgroup of LIM-type homeodomain proteins is characterized by 2 tandemly repeated LIM motifs. The LIM motif is a zinc-binding motif composed of 50 to 60 amino acid residues that contain a conserved pattern of cysteine and histidine residues that form a pair of zinc fingers separated by a linker of 2 amino acids. The LIM domain has been shown to bind Zn(2+). Most zinc-finger motifs function by binding to specific DNA sequences; however, the LIM domain has not been shown to have DNA-binding activity. Zhadanov et al. (1995) cloned and sequenced the mouse Lhx3 cDNA. They found that Lhx3 mRNA accumulates in the Rathke pouch, the primordium of the pituitary, at day 9.5 of mouse embryonic development. This suggested that the gene product may be involved in the establishment and maintenance of the differentiated phenotype of pituitary cells. Additional functions were suggested by the fact that Lhx3 is also expressed bilaterally along the spinal cord and the hindbrain at early stages of development.
See also: Xenopus Xlim-1 Page