title: Cyclin-dependent kinase-5 is involved in neuregulin-dependent activation of phosphatidylinositol 3-kinase and Akt activity mediating neuronal survival.
abstract: The phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway plays an important role in mediating survival signals in wide variety of neurons and cells. Recent studies show that Akt also regulates metabolic pathways to regulate cell survival. In this study, we reported that cyclin-dependent kinase-5 (Cdk5) regulates Akt activity and cell survival through the neuregulin-mediated PI 3-kinase signaling pathway. We found that brain extracts of Cdk5-/-mice display a lower PI 3-kinase activity and phosphorylation of Akt compared with that in wild type mice. Moreover, we demonstrated that Cdk5 phosphorylated Ser-1176 in the neuregulin receptor ErbB2 and phosphorylated Thr-871 and Ser-1120 in the ErbB3 receptor. We identified the Ser-1120 sequence RSRSPR in ErbB3 as a novel phosphorylation consensus sequence of Cdk5. Finally, we found that Cdk5 activity is involved in neuregulin-induced Akt activity and neuregulin-mediated neuronal survival. These findings suggest that Cdk5 may exert a key role in promoting neuronal survival by regulating Akt activity through the neuregulin/PI 3-kinase signaling pathway.
authors.affiliation: Laboratory of Neurochemistry, National Institute of Neurological Diseases and Stroke, National Institutes of Health, Bethesda, Maryland 20892-4130, USA.
authors.forename: Bing-Sheng
authors.initials: BS
authors.lastname: Li
authors.forename: Wu
authors.initials: W
authors.lastname: Ma
authors.forename: Howard
authors.initials: H
authors.lastname: Jaffe
authors.forename: Yali
authors.initials: Y
authors.lastname: Zheng
authors.forename: Satoru
authors.initials: S
authors.lastname: Takahashi
authors.forename: Lei
authors.initials: L
authors.lastname: Zhang
authors.forename: Ashok B
authors.initials: AB
authors.lastname: Kulkarni
authors.forename: Harish C
authors.initials: HC
authors.lastname: Pant
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D001921:Brain / Q000166:cytology / Q000196:embryology / Q000502:physiology; D019556:COS Cells; D002470:Cell Survival; D002522:Chlorocebus aethiops; D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D004622:Embryo, Mammalian; D004789:Enzyme Activation; D051379:Mice; D018345:Mice, Knockout; D020880:Neuregulins / Q000494:pharmacology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3 / Q000737:chemistry / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection
chemical_list: D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases; D020880:Neuregulins; D019869:Phosphatidylinositol 3-Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; D011994:Recombinant Proteins; C495906:Cdk5 protein, mouse