Demonstration of an activation regulated NF-kappaB/I-kappaBalpha complex in human platelets.
In eukaryotic cells, the ubiquity of the signaling system of transcription factor nuclear factor-kappa B (NF-kappaB)/I-kappa B (I-kappaB) is undisputed. Numerous studies have reported that the NF-kappaB/I-kappaB complex plays a pivotal role in regulating gene expression controlling cell differentiation, cell proliferation, inflammation, oncogenesis, and apoptosis. Here we show that NF-kappaB/I-kappaB families exist in human platelets, natural anuclear corpuscles derived from megakaryocytes. Moreover, the I-kappaB kinase (IKK) is present and may phosphorylate I-kappaB during platelet activation. Coupled with intracellular calcium flux, this leads to I-kappaB dissociation from the NF-kappaB/I-kappaB complex and proteolysis. The NF-kappaB/I-kappaB proteins may have function independent of gene regulation in platelets.
Liu
Fengqi
F
Department of Anesthesiology, Graduate School of Medicine, University of Tennessee Medical Center, 1924 Alcoa Highway, Knoxville, TN 37920, USA.
Morris
Steve
S
Epps
Jerry
J
Carroll
Roger
R
D001792:Blood Platelets / Q000737:chemistry / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D006801:Humans; D051550:I-kappa B Kinase; D020672:I-kappa B Proteins / Q000378:metabolism* / Q000502:physiology; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism* / Q000502:physiology; D010447:Peptide Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D015539:Platelet Activation / Q000502:physiology*; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000032:analysis
D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D000072000:NF-KappaB Inhibitor alpha; D017346:Protein Serine-Threonine Kinases; C496559:CHUK protein, human; D051550:I-kappa B Kinase; C496560:IKBKB protein, human; C496565:IKBKE protein, human; D010447:Peptide Hydrolases; D002118:Calcium