Two structurally distinct domains of the nucleoporin Nup170 cooperate to tether a subset of nucleoporins to nuclear pores.
How individual nucleoporins (Nups) perform their role in nuclear pore structure and function is largely unknown. In this study, we examined the structure of purified Nup170 to obtain clues about its function. We show that Nup170 adopts a crescent moon shape with two structurally distinct and separable domains, a beta-propeller N terminus and an alpha-solenoid C terminus. To address the individual roles of each domain, we expressed these domains separately in yeast. Notably, overexpression of the Nup170 C domain was toxic in nup170Delta cells and caused accumulation of several Nups in cytoplasmic foci. Further experiments indicated that the C-terminal domain anchors Nup170 to nuclear pores, whereas the N-terminal domain functions to recruit or retain a subset of Nups, including Nup159, Nup188, and Pom34, at nuclear pores. We conclude that Nup170 performs its role as a structural adapter between cytoplasmically oriented Nups and the nuclear pore membrane.
Centre for Biochemistry, University of Heidelberg, Heidelberg, Germany.
Dirk
D
Flemming
Phillip
P
Sarges
Philipp
P
Stelter
Andrea
A
Hellwig
Bettina
B
Böttcher
Ed
E
Hurt
D003593:Cytoplasm / Q000502:physiology; D004926:Escherichia coli / Q000235:genetics; D005690:Galactose / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D008854:Microscopy, Electron; D022022:Nuclear Pore / Q000502:physiology*; D028861:Nuclear Pore Complex Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure
C097178:NUP170 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D005947:Glucose; D005690:Galactose