FERM (Four.1 protein, Ezrin, Radixin, Moesin) domain, F1 sub-domain, found in kindlin-3 (KIND3)
KIND3, also termed fermitin family homolog 3 (FERMT3), or MIG2-like protein, or Unc-112-related protein 2, is an adaptor protein that expressed primarily in hematopoietic cells. It plays a central role in cell adhesion in hematopoietic cells, and also promotes integrin activation, clustering and outside-in signaling. KIND3, together with talin-1, contributes essentially to the activation of beta2-integrins in neutrophils. In addition, KIND3 interacts with the ribosome and regulates c-Myc expression required for proliferation of chronic myeloid leukemia cells. Mutations in the KIND3 gene cause leukocyte adhesion deficiency type III (LAD III), which is characterized by high susceptibility to infections, spontaneous and episodic bleedings, and osteopetrosis. KIND3 consists of an atypical FERM domain that is made up of F1, F2 and F3 domains, as well as an N-terminal region, which precedes the FERM domain and has been referred to as the F0 domain. This family corresponds to the F1 domain.