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Citation
Jannuzi, A.L., Bunch, T.A., West, R.F., Brower, D.L. (2004). Identification of integrin[] subunit mutations that alter heterodimer function in situ.  Mol. Biol. Cell 15(8): 3829--3840.
FlyBase ID
FBrf0179262
Publication Type
Research paper
Abstract

We conducted a genetic screen for mutations in myospheroid, the gene encoding the Drosophila betaPS integrin subunit, and identified point mutants in all of the structural domains of the protein. Surprisingly, we find that mutations in very strongly conserved residues will often allow sufficient integrin function to support the development of adult animals, including mutations in the ADMIDAS site and in a cytoplasmic NPXY motif. Many mutations in the I-like domain reduce integrin expression specifically when betaPS is combined with activating alphaPS2 cytoplasmic mutations, indicating that integrins in the extended conformation are unstable relative to the inactive, bent heterodimers. Interestingly, the screen has identified alleles that show gain-of-function characteristics in cell culture, but have negative effects on animal development or viability. This is illustrated by the allele mys(b58); available structural models suggest that the molecular lesion of mys(b58), V409>D, should promote the "open" conformation of the beta subunit I-like domain. This expectation is supported by the finding that alphaPS2betaPS (V409>D) promotes adhesion and spreading of S2 cells more effectively than does wild-type alphaPS2betaPS, even when betaPS is paired with alphaPS2 containing activating cytoplasmic mutations. Finally, comparisons with the sequence of human beta8 suggest that evolution has targeted the "mys(b58)" residue as a means of affecting integrin activity.

PubMed ID
PubMed Central ID
PMC491840 (PMC) (EuropePMC)
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    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Mol. Biol. Cell
    Title
    Molecular Biology of the Cell
    Publication Year
    1992-
    ISBN/ISSN
    1059-1524
    Data From Reference