Related Experiment Video
Updated: Aug 18, 2026

Time-resolved Förster Resonance Energy Transfer Assays for Measurement of Endogenous Phosphorylated STAT Proteins in Human Cells
Published on: September 9, 2021
Janus kinases affect thrombopoietin receptor cell surface localization and stability
Yohan Royer1, Judith Staerk, Marcel Costuleanu
1Ludwig Institute for Cancer Research, Brussels B-1200, Belgium.
Abstract:
The thrombopoietin receptor (TpoR) regulates hematopoietic stem cell renewal, megakaryocyte differentiation, and platelet formation. TpoR signals by activating Janus kinases JAK2 and Tyk2. Here we show that, in addition to signaling downstream from the activated TpoR, JAK2 and Tyk2 strongly promote cell surface localization and enhance total protein levels of the TpoR. This effect is caused by stabilization of the mature endoglycosidase H-resistant form of the receptor. Confocal microscopy indicates that TpoR colocalizes partially with recycling transferrin in Ba/F3 cells. The interaction with JAK2 or Tyk2 appears to protect the receptor from proteasome degradation. Sequences encompassing Box1 and Box2 regions of the receptor cytosolic domain and an intact JAK2 or Tyk2 FERM domain are required for these effects. We discuss the relevance of our results to the reported defects of TpoR processing in myeloproliferative diseases and to the mechanisms of Tpo signaling and clearance via the TpoR.
Related Concept Videos
The JAK-STAT Signaling Pathway
Intracellular Signaling Affects Focal Adhesions
Some...
Receptor Tyrosine Kinases
Amplifying Signals via Enzymatic Cascade
PI3K/mTOR/AKT Signaling Pathway
Receptor Downregulation in MVBs
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...

