Molecular basis for the functional interaction of dynein light chain with the nuclear-pore complex.
Nucleocytoplasmic transport occurs through nuclear pore complexes (NPCs) embedded in the nuclear envelope. Here, we discovered an unexpected role for yeast dynein light chain (Dyn2) in the NPC. Dyn2 is a previously undescribed nucleoporin that functions as molecular glue to dimerize and stabilize the Nup82-Nsp1-Nup159 complex, a module of the cytoplasmic pore filaments. Biochemical analyses showed that Dyn2 binds to a linear motif (termed DID(Nup159)) inserted between the Phe-Gly repeat and coiled-coil domain of Nup159. Electron microscopy revealed that the reconstituted Dyn2-DID(Nup159) complex forms a rigid rod-like structure, in which five Dyn2 homodimers align like 'pearls on a string' between two extented DID(Nup159) strands. These findings imply that the rigid 20 nm long Dyn2-DID(Nup159) filament projects the Nup159 Phe-Gly repeats from the Nup82 module. Thus, it is possible that dynein light chain plays a role in organizing natively unfolded Phe-Gly repeats within the NPC scaffold to facilitate nucleocytoplasmic transport.
Stelter
Philipp
P
Biochemie-Zentrum der Universität Heidelberg (BZH), Im Neuenheimer Feld 328, D-69120 Heidelberg, Germany.
Kunze
Ruth
R
Flemming
Dirk
D
Höpfner
Dominic
D
Diepholz
Meikel
M
Philippsen
Peter
P
Böttcher
Bettina
B
Hurt
Ed
E
D021581:Active Transport, Cell Nucleus; D002467:Cell Nucleus / Q000378:metabolism; D019281:Dimerization; D004398:Dyneins / Q000502:physiology*; D006801:Humans; D022022:Nuclear Pore / Q000502:physiology*; D028861:Nuclear Pore Complex Proteins / Q000502:physiology*; D011485:Protein Binding; D017510:Protein Folding; D017434:Protein Structure, Tertiary; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology*
C093510:NUP159 protein, S cerevisiae; C095897:NUP82 protein, S cerevisiae; D028861:Nuclear Pore Complex Proteins; D029701:Saccharomyces cerevisiae Proteins; D004398:Dyneins