Transmembrane receptors, cellular

The insulin receptor is a transmembrane receptor tyrosine kinase located in the plasma membrane of insulin-sensitive cells (e.g., adipocytes, myocytes, hepatocytes). It mediates the effect of insulin on specific cellular responses (e.g., glucose transport, glycogen synthesis, lipid synthesis, protein synthesis). 

For example, the growth factor receptor pathway involves an extracellular signal interacting with a transmembrane receptor. This then activates a tyrosine kinase causing phosphorylation of the receptor and allowing interaction with specific cellular proteins. This then sends a signal, which causes the expression of a particular gene. Oncoproteins alter this process. 

Integrins are a family of cellular transmembrane receptors that provide physical and biochemical bridges between components of the ECM (see... 

The receptor-like protein tyrosine phosphatases have a transmembrane and, in some cases, a large extracellular domain with a very variable structure (Fig. 8.19). Many, but not all, membrane protein tyrosine phosphatases have two catalytic domains in the cytoplasmic region. The overall structure is very similar to the structure of transmembrane receptors. Only recently, cellular ligands for receptor tyrosine phosphatases have been identified that function as their specific regulators. The receptor tyrosine phosphatase C has been found to be specifically inhibited by pleiotrophin, which is a cytokine implicated in tumor angiogenesis. Several studies have demonstrated a role for receptor PTPs in neuronal cell adhesion signaling pathways. In cells of the neural tissue, a surface protein, contactin, has been identified as an extracellular ligand of PTPa. 

EGER is a cellular transmembrane receptor with tyrosine kinase enzymatic activity, which plays a key role in human cancer. EGFR-dependent signaling is involved in... 

The B-cell receptor (BCR), a transmembrane receptor protein on the outer surface of B-cells, initiates the BCR pathway regulating several essential cellular processes including proliferation, differentiation, and apoptosis, which are critical for the functions and survival of both normal and malignant B cells.The BCR pathway involves multiple protein tyrosine kinases (PTKs), such as Lyn, Syk, and Bruton s tyrosine kinase (Btk). These PTKs have been found to be constitutively active and/or overexpressed that lead to uncontrolled proliferation and survival of malignant B cells. Btk, a kinase in the Tec family, is a unique therapeutic target. Upon BCR activation, Btk becomes activated by other PTKs, such as Lyn and/or Syk, resulting in activation of downstream events necessary for B-cell proliferation and differentiation. Inhibition of Btk activity prevents... 

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