The dependence receptor TrkC regulates the number of sensory neurons during DRG development.

The development of the sensory nervous system is the result of fine-tuned waves of neurogenesis and apoptosis which control the appropriate number of precursors and newly generated neurons and orient them toward a specific lineage. Neurotrophins and their tyrosine-kinase receptors (RTK) orchestrate this process. They have long been in the scope of the neurotrophic theory which established that a neuron is committed to die unless a trophic factor generated by its target provides it with a survival signal.

Hey1- and p53-dependent TrkC proapoptotic activity controls neuroblastoma growth.

The neurotrophin-3 (NT-3) receptor tropomyosin receptor kinase C (TrkC/NTRK3) has been described as a dependence receptor and, as such, triggers apoptosis in the absence of its ligand NT-3. This proapoptotic activity has been proposed to confer a tumor suppressor activity to this classic tyrosine kinase receptor (RTK). By investigating interacting partners that might facilitate TrkC-induced cell death, we have identified the basic helix-loop-helix (bHLH) transcription factor Hey1 and importin-α3 (karyopherin alpha 4 [KPNA4]) as direct interactors of TrkC intracellular domain, and we show that Hey1 is required for TrkC-induced apoptosis.

The dependence receptor TrkC triggers mitochondria-dependent apoptosis upon Cobra-1 recruitment.

The neurotrophin receptor TrkC was recently identified as a dependence receptor, and, as such, it triggers apoptosis in the absence of its ligand, NT-3. The molecular mechanism for apoptotic engagement involves the double cleavage of the receptor's intracellular domain, leading to the formation of a proapoptotic "killer" fragment (TrkC KF). Here, we show that TrkC KF interacts with Cobra1, a putative cofactor of BRCA1, and that Cobra1 is required for TrkC-induced apoptosis.

DCC constrains tumour progression via its dependence receptor activity.

The role of deleted in colorectal carcinoma (DCC) as a tumour suppressor has been a matter of debate for the past 15 years. DCC gene expression is lost or markedly reduced in the majority of advanced colorectal cancers and, by functioning as a dependence receptor, DCC has been shown to induce apoptosis unless engaged by its ligand, netrin-1 (ref. 2).