CUL7 gene encodes for a component of SCF-like E3 ubiquitin-protein ligase complex, which interacts with TP53, CUL9, and FBXW8 proteins. Such complexes usually mediate the ubiquitination and subsequent proteasomal degradation of target proteins. In the case of CUL7, target proteins are likely to be involved in endothelial proliferation and/or differentiation. In fact CUL7 was found to be involved in chondrocyte growth and proliferation. CUL7 protein has a central DOC domain and a C-terminal cullin domain, in addition to these a 72-amino acid domain enriched in glycine and acidic residues is located at the N-terminus of CUL7. The latter also contains an ATP/GTP-binding site motif A and motifs found in mitochondrial energy transfer proteins. CUL7 is usually expressed in a wide range of tissues and cell lines except testis and small intestine.
CUL7 mutations can lead to reduced cell mitosis during the early gestation period and consequently retarded growth, which is the central feature of the 3M syndrome-1. These mutations may disrupt the ability of CUL7 to assemble the components of the ubiquitin-proteasome system. Therefore, impaired ubiquitination may have a role in the pathogenesis of intrauterine growth retardation.