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Nucleocytoplasmic Trafficking Is Required for Functioning of the Adaptor Protein Sla1p in Endocytosis
Author(s) -
Gardiner Fiona C.,
Costa Rosaria,
Ayscough Kathryn R.
Publication year - 2007
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2007.00534.x
Subject(s) - endocytic cycle , endocytosis , importin , karyopherin , nuclear transport , microbiology and biotechnology , biology , signal transducing adaptor protein , nuclear localization sequence , nuclear pore , clathrin , nuclear protein , transport protein , clathrin adaptor proteins , cell nucleus , nucleus , cell , biochemistry , signal transduction , gene , transcription factor
Dual localization of proteins at the plasma membrane and within the nucleus has been reported in mammalian cells. Among these proteins are those involved in cell adhesion structures and in clathrin‐mediated endocytosis. In the case of endocytic proteins, trafficking to the nucleus is not known to play a role in their endocytic function. Here, we show localization of the yeast endocytic adaptor protein Sla1p to the nucleus as well as to the cell cortex and we demonstrate the importance of specific regions of Sla1p for this nuclear localization. A role for specific karyopherins (importins and exportins) in Sla1p nuclear localization is revealed. Furthermore, endocytosis of Sla1p‐dependent cargo is defective in three strains with karyopherin mutations. Finally, we investigate possible functions for nuclear trafficking of endocytic proteins. Our data reveal for the first time that nuclear transport of endocytic proteins is important for functional endocytosis in Saccharomyces cerevisiae . We determine the mechanism, involving an α/β importin pair, that facilitates uptake of Sla1p and demonstrate that nuclear transport is required for the functioning of Sla1p during endocytosis.