Summary
Surface receptors that dimerise on ligand binding and autophosphorylate, triggering cascades like the Ras-MAPK pathway.
In depth
Ligand binding causes receptor dimerisation and cross-phosphorylation of tyrosine residues. Phosphotyrosines recruit adaptor proteins such as Grb2, which activate Ras; Ras triggers a MAP kinase cascade (Raf, MEK, ERK) that ends in changes to gene expression and proliferation.
Other branches such as PI3K-Akt promote survival. Overactive RTKs, for instance EGFR and HER2, drive many cancers.
The family includes receptors for insulin, EGF, PDGF and VEGF. The insulin receptor is already a dimer and activates insulin receptor substrate proteins, linking to PI3K and glucose uptake. Duration and strength of signalling matter: sustained ERK activation can mean differentiation, while a short pulse means proliferation, in some cells.
Mutated RTKs are driving forces in cancer: HER2 is amplified in about 20 percent of breast cancers (targeted by trastuzumab) and EGFR is mutated in some lung cancers (targeted by gefitinib). Imatinib targets a related tyrosine kinase, BCR-ABL, in chronic myeloid leukaemia.
Remember: Ras is a small GTPase, and the mutation that blocks GTP hydrolysis keeps it permanently on.
Frequently asked questions
What is Receptor Tyrosine Kinases?
Surface receptors that dimerise on ligand binding and autophosphorylate, triggering cascades like the Ras-MAPK pathway.
Which area of biology covers Receptor Tyrosine Kinases, and how advanced is it?
Receptor Tyrosine Kinases is one of the 52 topics in Cell Biology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include G Protein-Coupled Receptors, Cell Signalling, Cancer Cell Biology.
Can you give an example of Receptor Tyrosine Kinases?
Trastuzumab (Herceptin) targets HER2 in breast cancer.
What should I learn before Receptor Tyrosine Kinases?
Work through the Beginner topics in Cell Biology first, such as Cell Theory, Prokaryotic Cell, Eukaryotic Cell, then return to Receptor Tyrosine Kinases. Advanced topics assume the Intermediate vocabulary.
What topics are related to Receptor Tyrosine Kinases?
The closest topics to Receptor Tyrosine Kinases are G Protein-Coupled Receptors, Cell Signalling, Cancer Cell Biology, Cyclin-Dependent Kinases. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Receptor Tyrosine Kinases?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Receptor Tyrosine Kinases. To practise the whole of Cell Biology, use the Cell Biology quiz.
How is Receptor Tyrosine Kinases different from G Protein-Coupled Receptors?
Receptor Tyrosine Kinases: Surface receptors that dimerise on ligand binding and autophosphorylate, triggering cascades like the Ras-MAPK pathway. G Protein-Coupled Receptors: Seven-transmembrane receptors that activate G proteins to generate second messengers such as cAMP. Read both side by side and note what each one explains.
How should I study Receptor Tyrosine Kinases step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with G Protein-Coupled Receptors and explain the difference aloud. Finally, take the Cell Biology quiz and come back to this page for any question you miss.