title: A tautomerase-null macrophage migration-inhibitory factor (MIF) gene knock-in mouse model reveals that protein interactions and not enzymatic activity mediate MIF-dependent growth regulation.
abstract: Macrophage migration-inhibitory factor (MIF) is an upstream regulator of innate immunity and a potential molecular link between inflammation and cancer. The unusual structural homology between MIF and certain tautomerases, which includes both a conserved substrate-binding pocket and a catalytic N-terminal proline (Pro1), has fueled speculation that an enzymatic reaction underlies MIF's biologic function. To address the functional role of the MIF tautomerase activity in vivo, we created a knock-in mouse in which the endogenous mif gene was replaced by one encoding a tautomerase-null, Pro1-->Gly1 MIF protein (P1G-MIF). While P1G-MIF is completely inactive catalytically, it maintains significant, albeit reduced, binding to its cell surface receptor (CD74) and to the intracellular binding protein JAB1/CSN5. P1G-MIF knock-in mice (mif(P1G/P1G)) and cells derived from these mice show a phenotype in assays of growth control and tumor induction that is intermediate between those of the wild type (mif(+/+)) and complete MIF deficiency (mif(-)(/)(-)). These data provide genetic evidence that MIF's intrinsic tautomerase activity is dispensable for this cytokine's growth-regulatory properties and support a role for the N-terminal region in protein-protein interactions.
authors.affiliation: Clinic I for Internal Medicine, Hematology and Oncology, University Hospital Cologne, Cologne, Germany.
authors.forename: Günter
authors.initials: G
authors.lastname: Fingerle-Rowson
authors.forename: Dayananda Rao
authors.initials: DR
authors.lastname: Kaleswarapu
authors.forename: Corinna
authors.initials: C
authors.lastname: Schlander
authors.forename: Nazanin
authors.initials: N
authors.lastname: Kabgani
authors.forename: Tania
authors.initials: T
authors.lastname: Brocks
authors.forename: Nina
authors.initials: N
authors.lastname: Reinart
authors.forename: Raymonde
authors.initials: R
authors.lastname: Busch
authors.forename: Anke
authors.initials: A
authors.lastname: Schütz
authors.forename: Hongqi
authors.initials: H
authors.lastname: Lue
authors.forename: Xin
authors.initials: X
authors.lastname: Du
authors.forename: Aihua
authors.initials: A
authors.lastname: Liu
authors.forename: Huabao
authors.initials: H
authors.lastname: Xiong
authors.forename: Yibang
authors.initials: Y
authors.lastname: Chen
authors.forename: Alice
authors.initials: A
authors.lastname: Nemajerova
authors.forename: Michael
authors.initials: M
authors.lastname: Hallek
authors.forename: Jürgen
authors.initials: J
authors.lastname: Bernhagen
authors.forename: Lin
authors.initials: L
authors.lastname: Leng
authors.forename: Richard
authors.initials: R
authors.lastname: Bucala
mesh_terms: D000483:Alleles; D019943:Amino Acid Substitution; D000818:Animals; D001564:Benzo(a)pyrene; D049109:Cell Proliferation; D002471:Cell Transformation, Neoplastic / Q000378:metabolism; D002478:Cells, Cultured; D004622:Embryo, Mammalian / Q000166:cytology; D047108:Embryonic Development; D005347:Fibroblasts / Q000166:cytology / Q000201:enzymology; D055879:Gene Knock-In Techniques; D018390:Gene Targeting; D011905:Genes, ras; D019746:Intramolecular Oxidoreductases / Q000172:deficiency* / Q000378:metabolism*; D008263:Macrophage Migration-Inhibitory Factors / Q000172:deficiency* / Q000378:metabolism*; D051379:Mice; D008954:Models, Biological; D010641:Phenotype; D011485:Protein Binding; D015398:Signal Transduction; D012878:Skin Neoplasms / Q000139:chemically induced / Q000201:enzymology / Q000473:pathology
chemical_list: D008263:Macrophage Migration-Inhibitory Factors; D001564:Benzo(a)pyrene; D019746:Intramolecular Oxidoreductases; C076231:Mif protein, mouse