Ezrin

Ezrin, also known as cytovillin or villin-2, is a cytoplasmic protein that in humans is encoded by the EZR gene. The N-terminus of ezrin contains a FERM domain. The C-terminus contains an ERM domain.

Ezrin can be phosphorylated by protein tyrosine kinase in the microvilli and is a member of the ezrin-radixin-moesin (ERM) protein family (Derouiche A et al. 2019). Ezrin links the cytoskeleton to cell surface integrins and plasma membrane receptors (Khan K et al 2020).

The protein plays a key role in adhesion, migration and organization of cell surface structures. The membrane proteins such as CD44 and ICAM-2 are indirect binding partners of ezrin, while EBP50 (ERM binding protein 50) can associate directly with ezrin. The molecular mechanisms of ERM (in)activation appear to be universal in mammalian cells. In contrast, the actual ezrin and radixin kinases, phosphatases, and binding partners are cell type specific.

In astrocytes, ezrin is involved in process motility, which can be stimulated by the neurotransmitter glutamate (Derouiche A et al. 2019).

In bronchial epithelial cells, ezrin downregulation is associated with IL-13-induced epithelial damage. Ezrin may be a potential biomarker for asthma control (Jia M et al 2019).

Tumor cells: Furthermore, ezrin contributes to the proliferative and metastatic potential of cancer cells. Increased ezrin expression in various cancers is associated with poor outcomes. Ezrin contributes to the secretion of factors that stimulate tumor cell migration, invasion, and clonogenic growth.

1. Derouiche A et al (2019) Perspectives for ezrin and radixin in astrocytes: kinases, functions and pathology. Int J Mol Sci 20:3776.
2. Jia M et al (2019) Ezrin, a membrane cytoskeleton cross-linker protein, as a marker of epithelial damage in asthma. Am J Respir Crit Care Med 199:496-507.
3. Khan K et al (2020) Bidirectional tumor-promoting activities of macrophage ezrin. Int J Mol Sci 21:7716.