Cas scaffolding protein family member 4 (CASS4)

Cas scaffolding protein family member 4 (CASS4) is a cytoplasmic scaffolding protein and the fourth member of the CAS (Crk-associated substrate) protein family in humans[1][6]. Structurally, it contains an N-terminal SH3 domain, an unstructured region with multiple SH2-binding motifs, and domains similar to the focal adhesion targeting (FAT) domain, facilitating interactions with proteins involved in cell adhesion such as focal adhesion kinase (FAK)[1][6]. CASS4 functions primarily as a docking/adaptor protein participating in tyrosine kinase-based signal transduction, affecting cell adhesion, motility, and cytoskeletal reorganization in a cell type-dependent manner[1][3][6]. Its expression is highest in spleen and lung, and is altered in various pathologies, including overexpression in metastatic non-small cell lung cancer and upregulation in eosinophilic asthma, while certain single nucleotide polymorphisms in CASS4 are associated with a reduced risk of Alzheimer’s disease and modifier roles in cystic fibrosis[1]. Currently, CASS4 has no known direct drug antagonists or therapies targeting it, because it lacks a catalytic domain or extracellular targetable structure; its main relevance is as a potential biomarker for patient stratification and disease prognosis[1][3][6].

Other names

CASS4C20orf32CAS4HEFLHEPLHEF-like proteinHEF1-EFS-p130Cas-like proteinHEF1-Efs-p130Cas-likeCas scaffold protein family member 4