title: Phosphorylation of c-Cbl and p85 PI3K driven by all-trans retinoic acid and CD38 depends on Lyn kinase activity.
abstract: The leukocyte antigen CD38 is expressed after all-trans retinoic acid (ATRA) treatment in HL-60 myelogenous leukemia cells and promotes induced myeloid differentiation when overexpressed. We found that Vav1 and SLP-76 associate with CD38 in two cell lines, and that these proteins complex with Lyn, a Src family kinase (SFK) upregulated by ATRA. SFK inhibitors PP2 and dasatinib, which enhance ATRA-induced differentiation, were used to evaluate the involvement of Lyn kinase activity in CD38-driven signaling. Cells treated with ATRA for 48h followed by one hour of PP2 incubation show SFK/Lyn kinase inhibition. We observed that Lyn inhibition blocked c-Cbl and p85/p55 PI3K phosphorylation driven by the anti-CD38 agonistic mAb IB4 in ATRA-treated HL-60 cells and untreated CD38+ transfectants. In contrast, cells cultured for 48h following concurrent ATRA and PP2 treatment did not show Lyn inhibition, suggesting ATRA regulates the effects on Lyn. 48h of co-treatment preserved CD38-stimulated c-Cbl and p85/p55 PI3K phosphorylation indicating Lyn kinase activity is necessary for these events. In contrast another SFK inhibitor (dasatinib) which blocks Lyn activity with ATRA co-treatment prevented ATRA-induced c-Cbl phosphorylation and crippled p85 PI3K phosphorylation, indicating Lyn kinase activity is important for ATRA-propelled events potentially regulated by CD38. We found that loss of Lyn activity coincided with a decrease in Vav1/Lyn/CD38 and SLP-76/Lyn/CD38 interaction, suggesting these molecules form a complex that regulates CD38 signaling. Lyn inhibition also reduced Lyn and CD38 binding to p85 PI3K, indicating CD38 facilitates a complex responsible for PI3K phosphorylation. Therefore, Lyn kinase activity is important for CD38-associated signaling that may drive ATRA-induced differentiation.
authors.affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Johanna
authors.initials: J
authors.lastname: Congleton
authors.affiliation: Boyce Thompson Institute for Plant Research, Tower Road, Ithaca, NY 14853, USA.
authors.forename: Miaoqing
authors.initials: M
authors.lastname: Shen
authors.affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA.
authors.forename: Robert
authors.initials: R
authors.lastname: MacDonald
authors.affiliation: Laboratory of Immunogenetics, Department of Medical Sciences, University of Torino Medical School, Via Santena 19, 10126 Torino, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Malavasi
authors.affiliation: Department of Biomedical Sciences, Cornell University, Ithaca, NY 14853, USA. Electronic address: ay13@cornell.edu.
authors.forename: Andrew
authors.initials: A
authors.lastname: Yen
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000096:biosynthesis / Q000378:metabolism*; D048868:Adaptor Proteins, Signal Transducing / Q000096:biosynthesis / Q000378:metabolism; D000970:Antineoplastic Agents / Q000494:pharmacology; D002454:Cell Differentiation / Q000187:drug effects; D045744:Cell Line, Tumor; D058543:Class Ia Phosphatidylinositol 3-Kinase / Q000378:metabolism*; D000069439:Dasatinib; D018922:HL-60 Cells; D006801:Humans; D007951:Leukemia, Myeloid / Q000188:drug therapy; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000378:metabolism*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010750:Phosphoproteins / Q000096:biosynthesis / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D050721:Proto-Oncogene Proteins c-cbl / Q000378:metabolism; D051567:Proto-Oncogene Proteins c-vav / Q000096:biosynthesis / Q000378:metabolism; D011743:Pyrimidines / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D014212:Tretinoin / Q000494:pharmacology*; D019061:src-Family Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*
chemical_list: C412373:AG 1879; D048868:Adaptor Proteins, Signal Transducing; D000970:Antineoplastic Agents; D008562:Membrane Glycoproteins; D010750:Phosphoproteins; D047428:Protein Kinase Inhibitors; D051567:Proto-Oncogene Proteins c-vav; D011743:Pyrimidines; C092947:SLP-76 signal Transducing adaptor proteins; D013844:Thiazoles; C496618:VAV1 protein, human; D014212:Tretinoin; D050721:Proto-Oncogene Proteins c-cbl; D019869:Phosphatidylinositol 3-Kinases; D058543:Class Ia Phosphatidylinositol 3-Kinase; C523442:PIK3R3 protein, human; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; C498154:CD38 protein, human; D051997:ADP-ribosyl Cyclase 1; C067419:CBL protein, human; D000069439:Dasatinib
keywords: All-trans retinoic acid; CD38 signaling; Lyn; Src family kinases