Cub domain

The CUB domains (CUB is an acronym for "complement C1r/C1s, Uegf, Bmp1") denote protein structural motifs with 110 amino acids, which can be detected almost exclusively in extracellular and cytoplasmic membrane-associated (Bork P et al. 1993). CUB domains play a role in protein-protein interactions. For example, in proteins of the complement cascade, in extracellular proteases or in cell surface proteins. An example for the function of CUB domains are the isoforms PDGF CC and PDGF DD, members of the PDGF/VEGF family. In PDGF CC and PDGF DD, the CUB domain is located at the N-termini of the PDGF C/D chains. These growth factors are present with bound CUB domain in an inactive form and are only activated when proteases cleave the CUB domain.

1. Bork P et al (1993) The CUB domain. A widespread module in development regulated proteins.J of Molecular Biology 231: 539-545