Related Experiment Video

Updated: Jul 12, 2026

A Simple Bioassay for the Evaluation of Vascular Endothelial Growth Factors
09:04

A Simple Bioassay for the Evaluation of Vascular Endothelial Growth Factors

Published on: March 15, 2016

Receptor-type protein-tyrosine phosphatase mu is expressed in specific vascular endothelial beds in vivo

C Bianchi1, F W Sellke, R L Del Vecchio

  • 1Cancer Biology Program, Department of Medicine, Department of Surgery, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts, 02215, USA. cbianchi@warren.med.harvard.edu

Experimental Cell Research
|March 30, 1999
PubMed

Insights

Receptor-type protein-tyrosine phosphatase mu (RPTPmu) is primarily located in vascular endothelial cells, particularly in arteries. This finding suggests RPTPmu may play a role in specific endothelial cell functions and cell-cell contact.

Area of Science:

  • Cell Biology
  • Vascular Biology
  • Biochemistry

Background:

  • Receptor-type protein-tyrosine phosphatase mu (RPTPmu) is an enzyme involved in cell signaling.
  • Its precise localization and function within different tissue types remain incompletely understood.

Purpose of the Study:

  • To investigate the tissue localization of RPTPmu using immunofluorescence.
  • To explore the potential role of RPTPmu in endothelial cell biology and cell-cell interactions.

Main Methods:

  • Immunofluorescence staining was employed to detect RPTPmu expression in various tissues.
  • Expression levels were analyzed in relation to endothelial cell markers like von Willebrand factor and VE-cadherin.
  • RPTPmu localization was examined in vivo and in endothelial cell cultures under different cell densities.

Main Results:

  • RPTPmu immunoreactivity was predominantly observed in vascular endothelial cells, with higher abundance in arteries compared to veins.
  • Expression patterns differed from von Willebrand factor but showed no difference in VE-cadherin expression.
  • RPTPmu localized to the lateral aspects and cell-cell contacts of endothelial cells, with expression increasing with cell density.
  • RPTPmu was also detected in bronchial and biliary epithelia and cardiocytes.

Conclusions:

  • RPTPmu serves as a novel marker for endothelial cell heterogeneity.
  • The findings suggest a potential role for RPTPmu in endothelial-specific functions, particularly those involving cell-cell contact.

More Related Videos

Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity10:41

Using a GFP-tagged TMEM184A Construct for Confirmation of Heparin Receptor Identity

Published on: February 17, 2017

Characterizing Modulators of Protease-Activated Receptors with a Calcium Mobilization Assay Using a Plate Reader07:13

Characterizing Modulators of Protease-Activated Receptors with a Calcium Mobilization Assay Using a Plate Reader

Published on: May 24, 2024

Related Concept Videos

Enzyme-linked Receptors01:00

Enzyme-linked Receptors

Enzyme-linked receptors are proteins that act as both receptor and enzyme, activating multiple intracellular signals. This is a large group of receptors that include the receptor tyrosine kinase (RTK) family. Many growth factors and hormones bind to and activate the RTKs.
Neurotrophin (NT) receptors are a family of RTKs, including trkA, trkB, and trkC (tropomyosin-related kinase) receptors. TrkA is specific for nerve growth factor (NGF), neurotrophin-6, and neurotrophin-7. TrkB binds...
Receptor Downregulation in MVBs01:15

Receptor Downregulation in MVBs

Multivesicular bodies (MVBs) are mature endosomes that sort ubiquitinated proteins and then fuse with lysosomes to degrade the sorted proteins. Epidermal growth factor (EGF) and its receptor (EGFR) form a complex that can be internalized through endocytosis, sorted into an MVB, and later degraded.
The EGFR can initiate signaling pathways that  lead to cell proliferation, migration, and differentiation. Overexpression of EGFR  stimulates cells to proliferate. Excessive  EGFR activation may...
Regulation of Angiogenesis and Blood Supply01:24

Regulation of Angiogenesis and Blood Supply

Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits.  Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
Receptor Tyrosine Kinases01:26

Receptor Tyrosine Kinases

Receptor tyrosine kinases or RTKs are membrane-bound receptors that phosphorylate specific tyrosine on protein substrates. RTKs regulate cellular growth, differentiation, survival, and migration. They contain an extracellular ligand binding domain, a transmembrane domain, and a cytosolic tail with intrinsic kinase activity. Several extracellular signaling molecules activate RTKs in one or more ways and relay the signal downstream. Ligands such as platelet-derived growth factor (PDGF) or...
MAPK Signaling Cascades01:07

MAPK Signaling Cascades

Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
Transducer Mechanism: Enzyme-Linked Receptors01:27

Transducer Mechanism: Enzyme-Linked Receptors

Enzyme-linked receptors are cell-surface receptors acting as an enzyme or associating with an enzyme intracellularly. They make excellent drug targets. Drugs can bind to the extracellular ligand-binding domain or directly affect their enzymatic domain and alter their activity.
Major types that are helpful drug targets include: