Biology subjects

Tveriakhina, L.

Publications and source records attributed to Tveriakhina, L..

2 recordsLinked to original sources

bioRxiv2023

Temporal Dynamics and Stoichiometry in Notch Signaling - from Notch Synaptic Complex Formation to NICD Nuclear Entry

Mammalian Notch signaling occurs when binding of Delta or Jagged to Notch stimulates proteolytic release of the Notch intracellular domain (NICD), which enters the nucleus to regulate target gene expression. To determine the temporal dynamics of events associated with Notch signaling under native conditions, we fluorescently tagged Notch and Delta at their endogenous genomic loci and visualized them upon pairing of receiver (Notch) and sender (Delta) cells as a function of time after cell contact. At contact sites, Notch and Delta immediately accumulated at 1:1 stoichiometry in synapses, which resolved by 15-20 min after contact. Synapse formation preceded entrance of the Notch extracellular domain into the sender cell and accumulation of NICD in the nucleus of the receiver cell, which approached a maximum after [~]45 min and was prevented by chemical and genetic inhibitors of signaling. These findings directly link Notch-Delta synapse dynamics to NICD production with unprecedented spatiotemporal precision.

cell biology↗

bioRxiv2022

A Spatiotemporal Notch Interaction Map from Membrane to Nucleus

Notch signaling relies on ligand-induced proteolysis to liberate a nuclear effector that drives cell fate decisions. The location and timing of individual steps required for proteolysis and movement of Notch from membrane to nucleus, however, remain unclear. Here, we use proximity labeling with quantitative multiplexed mass spectrometry to monitor the microenvironment of endogenous Notch2 after ligand stimulation in the presence of a gamma secretase inhibitor and then as a function of time after inhibitor removal. Our studies show that gamma secretase cleavage of Notch2 occurs in an intracellular compartment and that formation of nuclear complexes and recruitment of chromatin-modifying enzymes occurs within 45 minutes of inhibitor washout. This work provides a spatiotemporal map of unprecedented detail tracking the itinerary of Notch from membrane to nucleus after activation and identifies molecular events in signal transmission that are potential targets for modulating Notch signaling activity.

molecular biology↗