MSN Gene

The MSN gene (MSN stands for "membrane-organizing extension spike protein") is a protein (moesin) coding gene located on chromosome Xq12.

Moesin is a member of the ERM family (ezrin-radixin-moesin family), which also includes ezrin and radixin. ERM proteins appear to function as cross-linkers between plasma membranes and actin-based cytoskeletons (Huang L et al. 1999). Moesin is localized to filopodia and other membranous protrusions important for cell-cell recognition and signaling and cell movement.

Diseases associated with MSN include:

• Immunodeficiency 50 and MSN deficiency.

Moesin is increased in expression in various epithelial tumors but is also found in normal skin (Ichikawa T et al 1998).

Downstream signaling pathways include sensory processing of sound and nervous system development.

The role of moesin is particularly important in immunity, affecting both T and B cell homeostasis and self-tolerance, and regulating lymphocyte egress from lymphoid organs (Serrador JM et al 1997). Modulates phagolysosomal biogenesis in macrophages. Is also involved in the formation of immunological synapses (Lagresle-Peyrou C et al. 2016).

1. Huang L et al. (1999) Replacement of threonine 558, a critical site of phosphorylation of moesin in vivo, with aspartate activates F-actin binding of moesin. Regulation by conformational change. J Biol Chem 274:12803-12810.
2. Ichikawa T et al (1998) Expression of moesin and its associated molecule CD44 in epithelial skin tumors. J Cutan Pathol 25:237-243.
3. Lagresle-Peyrou C et al (2016) X-linked primary immunodeficiency associated with hemizygous mutations in the moesin (MSN) gene. J Allergy Clin Immunol 138:1681-1689.e8.
4. Serrador JM et al (1997) Moesin interacts with the cytoplasmic region of intercellular adhesion molecule-3 and is redistributed to the uropod of T lymphocytes during cell polarization. J Cell Biol 138:1409-1423.
5. Yu L et al (2019) Moesin is an independent prognostic marker for ER-positive breast cancer. Oncol Lett 17:1921-1933.