p75 and Trk: a two-receptor system.
The neurotrophin family of survival factors is distinguished by a unique receptor-signaling system that is composed of two transmembrane receptor proteins. Nerve growth factor (NGF), brain-derived neurotrophic factor, neurotrophin-3 (NT-3) and NT-4/5 share similar protein structures and biological functions and interact with two different types of cell-surface proteins, the Trk family of receptor tyrosine kinases, and the p75, or low-affinity neurotrophin receptor. An important question is whether a dual receptor system is necessary for neurotrophin action. Evidence indicates that co-expression of the two genes for the p75 receptor and the Trk NGF receptor can potentially lead to greater responsiveness to NGF, and suggests additional levels of regulation for the family of neurotrophin factors.
Chao
M V
MV
Dept of Cell Biology and Anatomy, Cornell University Medical College, New York, NY 10021, USA.
Hempstead
B L
BL
D000818:Animals; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000378:metabolism*; D020800:Receptor, Nerve Growth Factor; D020917:Receptor, trkA; D020813:Receptor, trkB; D017475:Receptors, Nerve Growth Factor / Q000378:metabolism*
D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins; D020800:Receptor, Nerve Growth Factor; D017475:Receptors, Nerve Growth Factor; D020794:Receptor Protein-Tyrosine Kinases; D020917:Receptor, trkA; D020813:Receptor, trkB