MSN

Moesin (for membrane-organizing extension spike protein) is a member of the ERM family which includes ezrin and radixin. ERM proteins appear to function as cross-linkers between plasma membranes and actin-based cytoskeletons. Moesin is localized to filopodia and other membranous protrusions that are important for cell-cell recognition and signaling and for cell movement. [provided by RefSeq, Jul 2008]

Moesin

Ezrin-radixin-moesin (ERM) family protein that connects the actin cytoskeleton to the plasma membrane and thereby regulates the structure and function of specific domains of the cell cortex. Tethers actin filaments by oscillating between a resting and an activated state providing transient interactions between moesin and the actin cytoskeleton (PubMed:10212266).

Once phosphorylated on its C-terminal threonine, moesin is activated leading to interaction with F-actin and cytoskeletal rearrangement (PubMed:10212266).

These rearrangements regulate many cellular processes, including cell shape determination, membrane transport, and signal transduction (PubMed:12387735, PubMed:15039356).

The role of moesin is particularly important in immunity acting on both T and B-cells homeostasis and self-tolerance, regulating lymphocyte egress from lymphoid organs (PubMed:9298994, PubMed:9616160).

Modulates phagolysosomal biogenesis in macrophages (By similarity).

Participates also in immunologic synapse formation (PubMed:27405666).

Cellular response to testosterone stimulus Source: UniProtKB
Establishment of endothelial barrier Source: UniProtKB
Establishment of epithelial cell apical/basal polarity Source: UniProtKB
Gland morphogenesis Source: UniProtKB
Immunological synapse formation Source: UniProtKB
Leukocyte cell-cell adhesion Source: BHF-UCL
Leukocyte migration Source: BHF-UCL
Membrane to membrane docking Source: BHF-UCL
Positive regulation of cellular protein catabolic process Source: UniProtKB
Positive regulation of early endosome to late endosome transport Source: UniProtKB
Positive regulation of gene expression Source: UniProtKB
Positive regulation of podosome assembly Source: Ensembl
Positive regulation of protein localization to early endosome Source: UniProtKB
Regulation of cell shape Source: UniProtKB
Regulation of cell size Source: UniProtKB
Regulation of lymphocyte migration Source: UniProtKB
Regulation of organelle assembly Source: UniProtKB
T cell aggregation Source: UniProtKB
T cell migration Source: UniProtKB
T cell proliferation Source: UniProtKB

Cytoskeleton
Plasma membrane
Cell membrane
Apical cell membrane
microvillus membrane
Other locations
microvillus
Note: Phosphorylated form is enriched in microvilli-like structures at apical membrane. Increased cell membrane localization of both phosphorylated and non-phosphorylated forms seen after thrombin treatment (By similarity). Localizes at the uropods of T lymphoblasts.

Immunodeficiency 50 (IMD50):
A primary immunodeficiency disorder characterized by onset of recurrent bacterial or varicella zoster virus infections in early childhood, profound lymphopenia, hypogammaglobulinemia, fluctuating monocytopenia and neutropenia, and a poor immune response to vaccine antigens.

Phosphorylation on Thr-558 is crucial for the formation of microvilli-like structures. Phosphorylation by ROCK2 suppresses the head-to-tail association of the N-terminal and C-terminal halves resulting in an opened conformation which is capable of actin and membrane-binding (By similarity). Phosphorylation on Thr-558 by STK10 negatively regulates lymphocyte migration and polarization.
S-nitrosylation of Cys-117 is induced by interferon-gamma and oxidatively-modified low-densitity lipoprotein (LDL(ox)) implicating the iNOS-S100A8/9 transnitrosylase complex.