The first LIM domain of Prickle 2: Prickle contains three C-terminal LIM domains and a N-terminal PET domain. Prickles have been implicated in roles of regulating tissue polarity or planar cell polarity (PCP). PCP establishment requires the conserved Frizzled/Dishevelled PCP pathway. Prickle interacts with Dishevelled, thereby modulating Frizzled/Dishevelled activity and PCP signaling. Four forms of prickles have been identified: prickle 1-4. The best characterized is prickle 1 and prickle 2 which are differentially expressed. While prickle 1 is expressed in fetal heart and hematological malignancies, prickle 2 is found in fetal brain, adult cartilage, pancreatic islet, and some types of timorous cells. Mutations in prickle 1 have been linked to progressive myoclonus epilepsy. LIM domains are 50-60 amino acids in size and share two characteristic zinc finger motifs. The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. LIM domains function as adaptors or scaffolds to support the assembly of multimeric protein complexes.
Comment: The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. The Zn binding residues of LIM domain are highly conserved.