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Citation
Cao, J., Li, Y., Xia, W., Reddig, K., Hu, W., Xie, W., Li, H.S., Han, J. (2011). A Drosophila metallophosphoesterase mediates deglycosylation of rhodopsin.  EMBO J. 30(18): 3701--3713.
FlyBase ID
FBrf0215269
Publication Type
Research paper
Abstract

Oligosaccharide chains of newly synthesized membrane receptors are trimmed and modified to optimize their trafficking and/or signalling before delivery to the cell surface. For most membrane receptors, the functional significance of oligosaccharide chain modification is unknown. During the maturation of Rh1 rhodopsin, a Drosophila light receptor, the oligosaccharide chain is trimmed extensively. Neither the functional significance of this modification nor the enzymes mediating this process are known. Here, we identify a dmppe (Drosophila metallophosphoesterase) mutant with incomplete deglycosylation of Rh1, and show that the retained oligosaccharide chain does not affect Rh1 localization or signalling. The incomplete deglycosylation, however, renders Rh1 more sensitive to endocytic degradation, and causes morphological and functional defects in photoreceptors of aged dmppe flies. We further demonstrate that the dMPPE protein functions as an Mn(2+)/Zn(2+)-dependent phosphoesterase and mediates in vivo dephosphorylation of α-Man-II. Most importantly, the dephosphorylated α-Man-II is required for the removal of the Rh1 oligosaccharide chain. These observations suggest that the glycosylation status of membrane proteins is controlled through phosphorylation/dephosphorylation, and that MPPE acts as the phosphoesterase in this regulation.

PubMed ID
PubMed Central ID
PMC3173788 (PMC) (EuropePMC)
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Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    EMBO J.
    Title
    The EMBO Journal
    Publication Year
    1982-
    ISBN/ISSN
    0261-4189
    Data From Reference
    Alleles (10)
    Gene Groups (1)
    Genes (14)
    Physical Interactions (1)
    Natural transposons (1)
    Insertions (2)
    Experimental Tools (2)
    Transgenic Constructs (7)