Primary megakaryocytes reveal a role for transcription factor NF-E2 in integrin alpha IIb beta 3 signaling. J Cell Biol 1999 Dec 27;147(7):1419-30
Date
12/30/1999Pubmed ID
10613901Pubmed Central ID
PMC2174239DOI
10.1083/jcb.147.7.1419Scopus ID
2-s2.0-0033611139 (requires institutional sign-in at Scopus site) 78 CitationsAbstract
Platelet integrin alphaIIbbeta3 responds to intracellular signals by binding fibrinogen and triggering cytoskeletal reorganization, but the mechanisms of alphaIIbbeta3 signaling remain poorly understood. To better understand this process, we established conditions to study alphaIIbbeta3 signaling in primary murine megakaryocytes. Unlike platelets, these platelet precursors are amenable to genetic manipulation. Cytokine-stimulated bone marrow cultures produced three arbitrary populations of alphaIIbbeta3-expressing cells with increasing size and DNA ploidy: small progenitors, intermediate-size young megakaryocytes, and large mature megakaryocytes. A majority of the large megakaryocytes bound fibrinogen in response to agonists, while almost none of the smaller cells did. Fibrinogen binding to large megakaryocytes was inhibited by Sindbis virus-mediated expression of isolated beta3 integrin cytoplasmic tails. Strikingly, large megakaryocytes from mice deficient in the transcription factor NF-E2 failed to bind fibrinogen in response to agonists, despite normal surface expression of alphaIIbbeta3. Furthermore, while megakaryocytes from wild-type mice spread on immobilized fibrinogen and exhibited filopodia, lamellipodia and Rho-dependent focal adhesions and stress fibers, NF-E2-deficient megakaryocytes adhered poorly. These studies establish that agonist-induced activation of alphaIIbbeta3 is controlled by NF-E2-regulated signaling pathways that mature late in megakaryocyte development and converge at the beta3 cytoplasmic tail. Megakaryocytes provide a physiologically relevant and tractable system for analysis of bidirectional alphaIIbbeta3 signaling.
Author List
Shiraga M, Ritchie A, Aidoudi S, Baron V, Wilcox D, White G, Ybarrondo B, Murphy G, Leavitt A, Shattil SAuthor
David A. Wilcox PhD Professor in the Pediatrics department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsBone Marrow Cells
Cell Differentiation
Cells, Cultured
DNA-Binding Proteins
Erythroid-Specific DNA-Binding Factors
Megakaryocytes
Mice
Mice, Inbred BALB C
Mice, Inbred C57BL
NF-E2 Transcription Factor
NF-E2 Transcription Factor, p45 Subunit
Nuclear Proteins
Platelet Glycoprotein GPIIb-IIIa Complex
Signal Transduction
Transcription Factors
