The fourth LIM domain of protein PINCH: PINCH plays a pivotal role in the assembly of focal adhesions (FAs), regulating diverse functions in cell adhesion, growth, and differentiation through LIM-mediated protein-protein interactions. PINCH comprises an array of five LIM domains that interact with integrin-linked kinase (ILK), Nck2 (also called Nckbeta or Grb4) and other interaction partners. These interactions are essential for triggering the FA assembly and for relaying diverse mechanical and biochemical signals between Cell-extracellular matrix and the actin cytoskeleton. The PINCH LIM4 domain recognizes the third SH3 domain of another adaptor protein, Nck2. This step is an important component of integrin signaling event. 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 assem bly 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.
Jiyao W et al.(2023). "The conserved domain database in 2023.",