Signaling endosome hypothesis: A cellular mechanism for long distance communication

The kinetics of signaling endosome retrograde transport along axons is analyzed and offered as evidence that such transport is more efficient than diffusion or calcium wave-based signaling systems over even relatively small distances. Evidence is provided to support the signaling endosome hypothesis and to expand the hypothesis to include signaling in many cell types and many cellular dimensions. Finally, a saltatory, regenerating inositol 1,4,5-trisphosphate wave model is offered to reconcile current discrepancies in the literature regarding endosomal-based retrograde signaling. (C) 2003 Wiley Periodicals, Inc.