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Swa2, the yeast homolog of mammalian auxilin, is specifically required for the propagation of the prion variant [ URE 3‐1 ]
Author(s) -
Troisi Elizabeth M.,
Rockman Michael E.,
Nguyen Phil P.,
Oliver Emily E.,
Hines Justin K.
Publication year - 2015
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13076
Subject(s) - biology , fungal prion , tetratricopeptide , chaperone (clinical) , yeast , microbiology and biotechnology , clathrin , biochemistry , endocytosis , saccharomyces cerevisiae , gene , cell , medicine , pathology
Summary Yeast prions require a core set of chaperone proteins including S is1, H sp70 and H sp104 to generate new amyloid templates for stable propagation, yet emerging studies indicate that propagation of some prions requires additional chaperone activities, demonstrating chaperone specificity beyond the common amyloid requirements. To comprehensively assess such prion‐specific requirements for the propagation of the [ URE 3 ] prion variant [ URE 3‐1 ], we screened 12 yeast cytosolic J ‐proteins, and here we report a novel role for the J ‐protein S wa2/ A ux1. Swa2 is the sole yeast homolog of the mammalian protein auxilin, which, like Swa2, functions in vesicle‐mediated endocytosis by disassembling the structural lattice formed by the protein clathrin. We found that, in addition to S is1, [ URE 3‐1 ] is specifically dependent upon S wa2, but not on any of the 11 other J ‐proteins. Further, we show that [ URE 3‐1 ] propagation requires both a functional J ‐domain and the tetratricopeptide repeat ( TPR ) domain, but surprisingly does not require S wa2‐clathrin binding. Because the J ‐domain of S wa2 can be replaced with the J ‐domains of other proteins, our data strongly suggest that prion‐chaperone specificity arises from the S wa2 TPR domain and supports a model where S wa2 acts through H sp70, most likely to provide additional access points for H sp104 to promote prion template generation.