Fc receptor-γ subunits with both polar or non-polar amino acids at position of T22 are capable of restoring surface expression of the high-affinity IgE receptor and degranulation in γ subunit-deficient rat basophilic leukemia cells

0390079 - ÚMG 2013 RIV GB eng J - Článek v odborném periodiku
Rashid, A. - Housden, J.E. - Helm, B.A. - Dráber, Petr
Fc receptor-γ subunits with both polar or non-polar amino acids at position of T22 are capable of restoring surface expression of the high-affinity IgE receptor and degranulation in γ subunit-deficient rat basophilic leukemia cells.
Molecular Immunology. Roč. 53, č. 3 (2013), s. 270-273. ISSN 0161-5890. E-ISSN 1872-9142
Grant CEP: GA MŠMT LD12073; GA ČR GA301/09/1826; GA ČR GAP302/10/1759; GA ČR(CZ) GBP302/12/G101; GA MŠMT 1M0506
Grant ostatní: European Cooperation in Science and Technology(XE) BM1007; AV ČR(CZ) M200520901
Výzkumný záměr: CEZ:AV0Z50520514
Klíčová slova: allergy * high-affinity IgE receptor * plasma membrane * transmembrane signaling * 3-helix assembly model
Kód oboru RIV: EB - Genetika a molekulární biologie
Impakt faktor: 3.003, rok: 2013

The high-affinity IgE receptor (FcɛRI) is formed by the IgE-binding α subunit, β subunit and γ subunits homodimer. All three subunits are required for proper expression of the receptor on the plasma membrane of mast cells and basophils. However, the exact molecular mechanism of inter-subunit interactions required for correct expression and function of the FcɛRI complex remains to be identified. A recent study suggested that polar aspartate at position 194 within the transmembrane domain of the α subunit could interact by hydrogen bonding with polar threonine at position 22 in the transmembrane domains of the γ subunits. To verify this, we used previously isolated rat basophilic leukemia (RBL)-2H3 variant cells deficient in the expression of the FcɛRI-γ subunit (FcR-γ), and transfected them with DNA vectors coding for FcR-γ of the wild-type or mutants in which T22 was substituted for nonpolar alanine (T22A mutant) or polar serine (T22S mutant). Analysis of the transfectants showed that both T22A and T22S mutants were capable to restore surface expression of the FcɛRI similar to wild-type FcR-γ. Furthermore, cells transfected with wild-type, T22A or T22S FcR-γ showed comparably enhanced FcɛRI-mediated degranulation. Our data indicate that substitution of FcR-γ T22 with non-polar amino acid does not interfere with surface expression of the FcɛRI and its signaling capacity.
Trvalý link: http://hdl.handle.net/11104/0218979