Ezrin also known as cytovillin or villin-2 is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...

that in humans is encoded by the ''EZR''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a ba ...

Structure

The

N-terminus The N-terminus (also known as the amino-terminus, NH2-terminus, N-terminal end or amine-terminus) is the start of a protein or polypeptide, referring to the free amine group (-NH2) located at the end of a polypeptide. Within a peptide, the ami ...

of ezrin contains a

FERM domain In molecular biology, the FERM domain (F for 4.1 protein, E for ezrin, R for radixin and M for moesin) is a widespread protein module involved in localising proteins to the plasma membrane. FERM domains are found in a number of cytoskeletal-ass ...

which is further subdivided into three subdomains. The

C-terminus The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is ...

contain an ERM domain.

Function

The

cytoplasmic In cell biology, the cytoplasm is all of the material within a eukaryotic cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. Th ...

peripheral protein Peripheral membrane proteins, or extrinsic membrane proteins, are membrane proteins that adhere only temporarily to the biological membrane with which they are associated. These proteins attach to integral membrane proteins, or penetrate the periph ...

encoded by this gene can be phosphorylated by protein-

tyrosine kinase A tyrosine kinase is an enzyme that can transfer a phosphate group from ATP to the tyrosine residues of specific proteins inside a cell. It functions as an "on" or "off" switch in many cellular functions. Tyrosine kinases belong to a larger cla ...

microvilli Microvilli (singular: microvillus) are microscopic cellular membrane protrusions that increase the surface area for diffusion and minimize any increase in volume, and are involved in a wide variety of functions, including absorption, secretion, ...

and is a member of the

ERM protein family The ERM protein family consists of three closely related proteins, ezrin, radixin and moesin. The three paralogs, ezrin, radixin and moesin, are present in vertebrates, whereas other species have only one ERM gene. Therefore, in vertebrates these ...

. This protein serves as a linker between plasma membrane and

actin Actin is a family of globular multi-functional proteins that form microfilaments in the cytoskeleton, and the thin filaments in muscle fibrils. It is found in essentially all eukaryotic cells, where it may be present at a concentration of over ...

cytoskeleton The cytoskeleton is a complex, dynamic network of interlinking protein filaments present in the cytoplasm of all cells, including those of bacteria and archaea. In eukaryotes, it extends from the cell nucleus to the cell membrane and is compos ...

. It plays a key role in cell surface structure adhesion, migration, and organization. The N-terminal domain (also called

) binds sodium-hydrogen exchanger regulatory factor (

NHERF Sodium-hydrogen antiporter 3 regulator 1 is a regulator of Sodium-hydrogen antiporter 3. It is encoded by the gene ''SLC9A3R1''. It is also known as ERM Binding Protein 50 (EBP50) or Na+/H+ Exchanger Regulatory Factor (NHERF1). It is believed t ...

) protein (involving long-range

allostery In biochemistry, allosteric regulation (or allosteric control) is the regulation of an enzyme by binding an effector molecule at a site other than the enzyme's active site. The site to which the effector binds is termed the ''allosteric site ...

). This binding can happen only when ezrin is in its active state. The activation of ezrin occurs in synergism of the two factors: 1) binding of the N-terminal domain to phosphatidylinositol(4,5)bis-phosphate (

PIP2 Phosphatidylinositol 4,5-bisphosphate or PtdIns(4,5)''P''2, also known simply as PIP2 or PI(4,5)P2, is a minor phospholipid component of cell membranes. PtdIns(4,5)''P''2 is enriched at the plasma membrane where it is a substrate for a number of ...

) and 2) phosphorylation of threonine T567 in the C-terminal domain. Binding to

actin filament Microfilaments, also called actin filaments, are protein filaments in the cytoplasm of eukaryotic cells that form part of the cytoskeleton. They are primarily composed of polymers of actin, but are modified by and interact with numerous other pro ...

s (via C-terminal) and to membrane proteins (via N-terminal) stabilizes the protein's conformation in its active mode. The membrane proteins like

CD44 The CD44 antigen is a cell-surface glycoprotein involved in cell–cell interactions, cell adhesion and migration. In humans, the CD44 antigen is encoded by the ''CD44'' gene on chromosome 11. CD44 has been referred to as HCAM (homing cell adhesi ...

and

ICAM-2 Intercellular adhesion molecule 2 (ICAM2), also known as CD102 (Cluster of Differentiation 102), is a human gene, and the protein resulting from it. Protein structure The protein encoded by this gene is a member of the intercellular adhesion mol ...

are indirect binding partners of ezrin, while EBP50 (ERM binding protein 50) can associate with ezrin directly.

Interactions

VIL2 has been shown to

interact Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization using innovative strategies to advocate for the legal and human rights of children with intersex traits. The organizati ...

with: *

CD43 Leukosialin also known as sialophorin or CD43 (cluster of differentiation 43) is a transmembrane cell surface protein that in humans is encoded by the ''SPN'' (sialophorin) gene. Function Sialophorin (leukosialin) is a major sialoglycoprotein ...

, * FASLG, *

ICAM-1 ICAM-1 (Intercellular Adhesion Molecule 1) also known as CD54 (Cluster of Differentiation 54) is a protein that in humans is encoded by the ''ICAM1'' gene. This gene encodes a cell surface glycoprotein which is typically expressed on endothelial ...

, *

ICAM2 Intercellular adhesion molecule 2 (ICAM2), also known as CD102 (Cluster of Differentiation 102), is a human gene, and the protein resulting from it. Protein structure The protein encoded by this gene is a member of the intercellular adhesion mol ...

, *

ICAM3 Intercellular adhesion molecule 3 (ICAM3) also known as CD50 (Cluster of Differentiation 50), is a protein that in humans is encoded by the ''ICAM3'' gene. The protein is constitutively expressed on the surface of leukocytes, which are also called ...

, *

Merlin Merlin ( cy, Myrddin, kw, Marzhin, br, Merzhin) is a mythical figure prominently featured in the legend of King Arthur and best known as a mage, with several other main roles. His usual depiction, based on an amalgamation of historic and le ...

, *

MSN MSN (meaning Microsoft Network) is a web portal and related collection of Internet services and apps for Windows and mobile devices, provided by Microsoft and launched on August 24, 1995, alongside the release of Windows 95. The Microsoft Net ...

, *

PIK3R1 Phosphatidylinositol 3-kinase regulatory subunit alpha is an enzyme that in humans is encoded by the ''PIK3R1'' gene. Function Phosphatidylinositol 3-kinase phosphorylates the inositol ring of phosphatidylinositol at the 3-prime position. The e ...

, * PALLD *

S100P S100 calcium-binding protein P (S100P) is a protein that in humans is encoded by the ''S100P'' gene. Function The protein encoded by this gene is a member of the S100 family of proteins containing 2 EF-hand calcium-binding motifs. S100 protei ...

, *

SDC2 Syndecan-2 is a protein that in humans is encoded by the ''SDC2'' gene. Function The protein encoded by this gene is a transmembrane (type I) heparan sulfate proteoglycan and is a member of the syndecan proteoglycan family. The syndecans medi ...

, * SLC9A3R1, * SLC9A3R2, and *

VCAM-1 Vascular cell adhesion protein 1 also known as vascular cell adhesion molecule 1 (VCAM-1) or cluster of differentiation 106 (CD106) is a protein that in humans is encoded by the ''VCAM1'' gene. VCAM-1 functions as a cell adhesion molecule. Stru ...

Structure

Function

Interactions

References

Further reading