Cellular mechanisms of signal transduction for neurotrophins.
The molecular cloning of new neuroactive growth factors and their receptors has greatly enhanced our understanding of important interactions among receptors and signaling molecules. These studies have begun to illuminate some of the mechanisms that allow for specificity in neuronal signaling. Model cell systems, such as the PC-12 pheochromocytoma cell line, express receptors for these different neurotrophic factors, leading to comparisons of signaling pathways for these factors. Upon binding their ligands, these receptors undergo phosphorylation on tyrosine residues, which directs their interaction with signaling proteins containing src homology (SH2) domains, sequences that mediate associations with tyrosine-phosphorylated proteins. These SH2 proteins translate the tyrosine kinase activity of receptors into downstream events that result in the specific cellular response. Investigations such as these have revealed that molecular specificity in signaling pathways may arise from combinatorial diversity in interactions between receptors and key regulatory proteins.
Saltiel
A R
AR
Department of Signal Transduction, Parke-Davis Pharmaceutical Research Division of Warner-Lambert Co., Ann Arbor, Michigan 48105.
Decker
S J
SJ
D000595:Amino Acid Sequence; D000818:Animals; D019208:Brain-Derived Neurotrophic Factor; D016384:Consensus Sequence; D008954:Models, Biological; D008969:Molecular Sequence Data; D005810:Multigene Family; D009414:Nerve Growth Factors / Q000494:pharmacology / Q000502:physiology*; D009419:Nerve Tissue Proteins / Q000502:physiology; D009424:Nervous System Physiological Phenomena; D020933:Neurotrophin 3; D016716:PC12 Cells; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D017346:Protein Serine-Threonine Kinases / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000502:physiology*; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000502:physiology*; D020801:Receptor, Ciliary Neurotrophic Factor; D020917:Receptor, trkA; D020812:Receptor, trkC; D017475:Receptors, Nerve Growth Factor / Q000502:physiology*; D015398:Signal Transduction / Q000502:physiology
D019208:Brain-Derived Neurotrophic Factor; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D020933:Neurotrophin 3; D011518:Proto-Oncogene Proteins; D020801:Receptor, Ciliary Neurotrophic Factor; D017475:Receptors, Nerve Growth Factor; D020794:Receptor Protein-Tyrosine Kinases; D020917:Receptor, trkA; D020812:Receptor, trkC; D017346:Protein Serine-Threonine Kinases; C073922:neurotrophin 4