Receptor-type tyrosine-protein phosphatase beta or VE-PTP is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

specifically expressed in endothelial cells that in humans is encoded by the ''PTPRB''

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 b ...

Function

VE-PTP is a member of the classical

protein tyrosine phosphatase Protein tyrosine phosphatases (EC 3.1.3.48, systematic name protein-tyrosine-phosphate phosphohydrolase) are a group of enzymes that remove phosphate groups from phosphorylated tyrosine residues on proteins: : proteintyrosine phosphate + H2O = ...

(PTP) family. The deletion of the gene in mouse models was shown to be embryonically lethal, thus indicating that it is important for

vasculogenesis Vasculogenesis is the process of blood vessel formation, occurring by a '' de novo'' production of endothelial cells. It is sometimes paired with angiogenesis, as the first stage of the formation of the vascular network, closely followed by ang ...

and blood vessel development. In addition, it was shown to participate in

adherens junctions Adherens junctions (or zonula adherens, intermediate junction, or "belt desmosome") are protein complexes that occur at cell–cell junctions, cell–matrix junctions in epithelial and endothelial tissues, usually more basal than tight junctions. ...

complex and regulate

vascular permeability Vascular permeability, often in the form of capillary permeability or microvascular permeability, characterizes the capacity of a blood vessel wall to allow for the flow of small molecules (drugs, nutrients, water, ions) or even whole cells (lymph ...

. Recently, Soni et al. have shown that tyrosine phosphorylation of VE-PTP via

Pyk2 Protein tyrosine kinase 2 beta is an enzyme that in humans is encoded by the ''PTK2B'' gene. Function This gene encodes a cytoplasmic protein tyrosine kinase that is involved in calcium-induced regulation of ion channels and activation of the ...

kinase downstream of

STIM1 Stromal interaction molecule 1 is a protein that in humans is encoded by the ''STIM1'' gene. STIM1 has a single transmembrane domain, and is localized to the endoplasmic reticulum, and to a lesser extent to the plasma membrane. Even though the pro ...

-induced calcium entry mediates disassembly of the endothelial

Interactions

VE-PTP contains an extracellular domain composed of multiple fibronectin type_III repeats, a single transmembrane segment and one intracytoplasmic catalytic domain, thus belongs to R3 receptor subtype PTPs. The extracellular region was shown to interact with the angiopoietin receptor

Tie-2 The angiopoietin receptors are receptors that bind angiopoietin. TIE-1 and TIE-2 comprise the cell-surface receptors that bind and are activated by the angiopoietins, (Ang1, Ang2, Ang3, Ang4). The angiopoietins are protein growth factors r ...

and with the adhesion protein

VE-cadherin Cadherin 5, type 2 or VE-cadherin (vascular endothelial cadherin) also known as CD144 ( Cluster of Differentiation 144), is a type of cadherin. It is encoded by the human gene ''CDH5''. Function VE-cadherin is a classical cadherin from the cad ...

. VE-PTP was also found to interact with Grb2 and

plakoglobin Plakoglobin, also known as junction plakoglobin or gamma-catenin, is a protein that in humans is encoded by the ''JUP'' gene. Plakoglobin is a member of the catenin protein family and homologous to β-catenin. Plakoglobin is a cytoplasmic compone ...

through its cytoplasmatic domain.

Role in disease

Dysregulation of PTPRB correlates with the development of a variety of tumors. PTPRB promotes metastasis of colorectal cancer cells via inducing epithelial-mesenchymal transition (EMT).

Function

Interactions

Role in disease

References

Further reading