| Autor: |
Costaguta, G., Stefan, C. J., Bensen, E. S., Emr, S. D., Payne, G. S. |
| Zdroj: |
Molecular Biology of the Cell; June 2001, Vol. 12 Issue: 6 p1885-1896, 12p |
| Abstrakt: |
Gga proteins represent a newly recognized, evolutionarily conserved protein family with homology to the “ear” domain of the clathrin adaptor AP-1 γ subunit. Yeast cells contain two Gga proteins, Gga1p and Gga2p, that have been proposed to act in transport between thetrans-Golgi network and endosomes. Here we provide genetic and physical evidence that yeast Gga proteins function in trans-Golgi network clathrin coats. Deletion of Gga2p (gga2Δ), the major Gga protein, accentuates growth and α-factor maturation defects in cells carrying a temperature-sensitive allele of the clathrin heavy chain gene. Cells carrying eithergga2Δ or a deletion of the AP-1 β subunit gene(apl2Δ)alone are phenotypically normal, but cells carrying both gga2Δ andapl2Δ are defective in growth, α-factor maturation, and transport of carboxypeptidase S to the vacuole. Disruption of bothGGAgenes and APL2results in cells so severely compromised in growth that they form only microcolonies. Gga proteins can bind clathrin in vitro and cofractionate with clathrin-coated vesicles. Our results indicate that yeast Gga proteins play an important role in cargo-selective clathrin-mediated protein traffic from the trans-Golgi network to endosomes. |
| Databáze: |
Supplemental Index |
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