title: Association of CD38 with nonmuscle myosin heavy chain IIA and Lck is essential for the internalization and activation of CD38.
abstract: Activation of CD38 in lymphokine-activated killer (LAK) cells involves interleukin-8 (IL8)-mediated protein kinase G (PKG) activation and results in an increase in the sustained intracellular Ca(2+) concentration ([Ca(2+)](i)), cADP-ribose, and LAK cell migration. However, direct phosphorylation or activation of CD38 by PKG has not been observed in vitro. In this study, we examined the molecular mechanism of PKG-mediated activation of CD38. Nonmuscle myosin heavy chain IIA (MHCIIA) was identified as a CD38-associated protein upon IL8 stimulation. The IL8-induced association of MHCIIA with CD38 was dependent on PKG-mediated phosphorylation of MHCIIA. Supporting these observations, IL8- or cell-permeable cGMP analog-induced formation of cADP-ribose, increase in [Ca(2+)](i), and migration of LAK cells were inhibited by treatment with the MHCIIA inhibitor blebbistatin. Binding studies using purified proteins revealed that the association of MHCIIA with CD38 occurred through Lck, a tyrosine kinase. Moreover, these three molecules co-immunoprecipitated upon IL8 stimulation of LAK cells. IL8 treatment of LAK cells resulted in internalization of CD38, which co-localized with MHCIIA and Lck, and blebbistatin blocked internalization of CD38. These findings demonstrate that the association of phospho-MHCIIA with Lck and CD38 is a critical step in the internalization and activation of CD38.
authors.affiliation: Department of Biochemistry, Chonbuk National University Medical School, Jeonju 561-182, Republic of Korea.
authors.forename: So-Young
authors.initials: SY
authors.lastname: Rah
authors.forename: Kwang-Hyun
authors.initials: KH
authors.lastname: Park
authors.forename: Tae-Sik
authors.initials: TS
authors.lastname: Nam
authors.forename: Sang-Jin
authors.initials: SJ
authors.lastname: Kim
authors.forename: Hyuntae
authors.initials: H
authors.lastname: Kim
authors.forename: Mie-Jae
authors.initials: MJ
authors.lastname: Im
authors.forename: Uh-Hyun
authors.initials: UH
authors.lastname: Kim
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000187:drug effects / Q000502:physiology*; D036563:Cyclic ADP-Ribose / Q000378:metabolism; D006152:Cyclic GMP / Q000494:pharmacology; D017869:Cyclic GMP-Dependent Protein Kinases / Q000378:metabolism; D006576:Heterocyclic Compounds, 4 or More Rings / Q000494:pharmacology; D006801:Humans; D016209:Interleukin-8 / Q000494:pharmacology; D019169:Jurkat Cells; D015979:Killer Cells, Lymphokine-Activated / Q000166:cytology / Q000201:enzymology*; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck) / Q000037:antagonists & inhibitors / Q000378:metabolism*; D024507:Nonmuscle Myosin Type IIA / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D011499:Protein Processing, Post-Translational / Q000187:drug effects / Q000502:physiology*
chemical_list: D006576:Heterocyclic Compounds, 4 or More Rings; D016209:Interleukin-8; D036563:Cyclic ADP-Ribose; C472645:blebbistatin; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D017869:Cyclic GMP-Dependent Protein Kinases; D051997:ADP-ribosyl Cyclase 1; D024507:Nonmuscle Myosin Type IIA; D006152:Cyclic GMP; D002118:Calcium