title: T-cell immunoglobulin and mucin domain 2 (TIM-2) is a target of ADAM10-mediated ectodomain shedding.
abstract: T-cell immunoglobulin and mucin domain (TIM)-2 is expressed on activated B cells. Here, we provide evidence that murine TIM-2 is a target of ADAM10-mediated ectodomain shedding, resulting in the generation of a soluble form of TIM-2. We identified ADAM10 but not ADAM17 as the major sheddase of TIM-2, as shown by pharmacological ADAM10 inhibition and with ADAM10-deficient and ADAM17-deficient murine embryonic fibroblasts. Ionomycin-induced or 2'(3')-O-(4-benzoylbenzoyl) ATP triethylammonium salt-induced shedding of TIM-2 was abrogated by deletion of 10 juxtamembrane amino acids from the stalk region but not by deletion of two further N-terminally located blocks of 10 amino acids, indicating a membrane-proximal cleavage site. TIM-2 lacking the intracellular domain was cleaved after ionomycin or 2' (3')-O-(4-benzoylbenzoyl) ATP triethylammonium salt treatment, indicating that this domain was not involved in the regulation of ectodomain shedding. Moreover, TIM-2 shedding was negatively controlled by calmodulin. Shed and soluble TIM-2 interacted with H-ferritin. In summary, we describe TIM-2 as a novel target for ADAM10-mediated ectodomain shedding, and reveal the involvement of ADAM proteases in cellular iron homeostasis.
authors.affiliation: Institute of Biochemistry, Medical Faculty, Christian Albrechts University, Kiel, Germany.
authors.forename: Christin
authors.initials: C
authors.lastname: Dewitz
authors.forename: Katja
authors.initials: K
authors.lastname: Möller-Hackbarth
authors.forename: Olga
authors.initials: O
authors.lastname: Schweigert
authors.forename: Karina
authors.initials: K
authors.lastname: Reiss
authors.forename: Athena
authors.initials: A
authors.lastname: Chalaris
authors.forename: Jürgen
authors.initials: J
authors.lastname: Scheller
authors.forename: Stefan
authors.initials: S
authors.lastname: Rose-John
mesh_terms: D051722:ADAM Proteins / Q000235:genetics / Q000378:metabolism*; D000072197:ADAM10 Protein; D053829:Amyloid Precursor Protein Secretases / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001052:Apoferritins / Q000378:metabolism*; D001402:B-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D015153:Blotting, Western; D019556:COS Cells; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism*; D049109:Cell Proliferation; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D005434:Flow Cytometry; D057809:HEK293 Cells; D006801:Humans; D047468:Immunoprecipitation; D015759:Ionomycin / Q000494:pharmacology; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009154:Mutation / Q000235:genetics
chemical_list: D002147:Calmodulin; D008565:Membrane Proteins; C442242:Timd2 protein, mouse; D015759:Ionomycin; D001052:Apoferritins; D053829:Amyloid Precursor Protein Secretases; D051722:ADAM Proteins; D000072197:ADAM10 Protein; C491234:Adam10 protein, mouse
keywords: ADAM10; T-cell immunoglobulin and mucin domain 2; calmodulin; ferritin; shedding