Sec13 is a subunit of the Nup84 (Nup107-160 complex in higher eukaryotes) nuclear pore subcomplex []and the the SEA complex (GATOR1 complex in higher eukaryotes) [, , ]. Besides Nup84 and SEA complexes, Sec13 is also part of the COPII vesicle coat required for ER-to-Golgi transport [, ].The Nup107-160 complex, which is the major structural subcomplex of the nuclear pore complex (NPC), functions in the regulation of mRNA export as well as in the assembly and distribution of NPCs within the nuclear envelope, and may also have functions independent of nucleocytoplasmic transport [].In budding yeasts, the SEA complex associates with the vacuole and is involved in intracellular trafficking, amino acid biogenesis, and response to nitrogen starvation []. In Drosophila, GATOR1 complex inhibits TORC1 activity in response to amino acid limitation and contributes to multiple aspects of the development []. Both Sec13 and Seh1 are positive regulators of TORC1 signalling [].
This entry includes nucleoporin Nup37, a component of the Nup107-160 subcomplex of the nuclear pore complex (NPC). Nup107-160 is required for assembly of a functional NPC, as well as normal kinetochore microtubule attachment, mitotic progression and chromosome segregation []. The vertebrate Nup107-160 complex includes NUP160, NUP133, NUP107, NUP98, NUP85, NUP43, NUP37, SEH1 and SEC13 []. This entry also includes some uncharacterised fungal proteins.
Seh1 and Sec13 are WD40 repeat containing proteins. They are subunits of the Nup84 (Nup107-160 complex in higher eukaryotes) nuclear pore subcomplex []and the the SEA complex (GATOR1 complex in higher eukaryotes) [, , ]. The Nup107-160 complex, which is the major structural subcomplex of the nuclear pore complex (NPC), functions in the regulation of mRNA export as well as in the assembly and distribution of NPCs within the nuclear envelope, and may also have functions independent of nucleocytoplasmic transport [].In budding yeasts, the SEA complex associates with the vacuole and is involved in intracellular trafficking, amino acid biogenesis, and response to nitrogen starvation []. In Drosophila, GATOR1 complex inhibits TORC1 activity in response to amino acid limitation and contributes to multiple aspects of the development []. Besides Nup84 and SEA complexes, Sec13 is also part of the COPII vesicle coat required for ER-to-Golgi transport [, ].
Nup84 forms a complex with five proteins, including Nup120, Nup85, Sec13, and a Sec13 homologue. This Nup84 complex in conjunction with Sec13-type proteins is required for correct nuclear pore biogenesis []. Nup107 is the vertebrate homologue of Nup84. The Nup107-160 complex (Nup84 complex in yeast) forms the cytoplasmic and nucleoplasmic rings of the nuclear pore complex (NPC) scaffold, which consists of three stacked rings [].
Sec31 is a component of the COPII coat complex that mediates formation of transport vesicles from the ER. The central α-helical unit of Sec31 is structurally similar to four large architectural nucleoporins. This α-helical unit, common to COPII and nuclear pore complex proteins, has been termed the ancestral coatomer element 1 (ACE1) []. This entry represents the ACE1 element found in Sec31 and Sec16, which also contains an ACE1 []. The ACE1 element of Sec31 can functionally replace that of Sec16. Both Sec31 and Sec16 bind to Sec13 [].
This entry represents the Nuclear pore complex protein Nup96 from animals its homologues from yeast and plants.Nuclear pore complexes (NPCs) facilitate all nucleocytoplasmic transport in eukaryotic cells, playing essential roles in cellular homeostasis. The NPC is a modular structure composed of multiple copies of ~30 proteins (nucleoporins, Nups) arranged into distinct subcomplexes [, ]. A number of these peptides are synthesised as precursors and undergo self-catalyzed cleavage. The largest NPC sub-complex is the heptameric Y-shaped mammalian Nup107-Nup160 complex (called Nup84 complex in budding yeast), an essential scaffolding component of the NPC [, , ]. Nup98 and Nup96 are encoded by the same gene that produces a 190 kDa polyprotein with autoproteolytic activity which generates the N-terminal NUP98 and C-terminal NUP96 proteins, part of the Nup107-Nup160 subcomplex [, ]. The yeast homologue Nup145 undergoes the similar proteolytic event to produce Nup145N and Nup145C, which are part of the Nup84 complex. The function of the heptamer is to coat the curvature of the nuclear pore complex between the inner and outer nuclear membranes. Nup96, which is predicted to be an alpha helical solenoid, complexes with Sec13 in the middle of the heptamer. The interaction between Nup96 and Sec13 is the point of curvature in the heptameric complex [, ].
Seh1 is a subunit of the Nup84 (Nup107-160 complex in higher eukaryotes) nuclear pore subcomplex []and the the SEA complex (GATOR1 complex in higher eukaryotes) [, , ]. The Nup107-160 complex, which is the major structural subcomplex of the nuclear pore complex (NPC), functions in the regulation of mRNA export as well as in the assembly and distribution of NPCs within the nuclear envelope, and may also have functions independent of nucleocytoplasmic transport [].In budding yeasts, the SEA complex associates with the vacuole and is involved in intracellular trafficking, amino acid biogenesis, and response to nitrogen starvation []. In Drosophila, GATOR1 complex inhibits TORC1 activity in response to amino acid limitation and contributes to multiple aspects of the development []. Both Sec13 and Seh1 are positive regulators of TORC1 signalling [].
Nuclear pore complexes (NPCs) facilitate all nucleocytoplasmic transport in eukaryotic cells, playing essential roles in cellular homeostasis. The NPC is a modular structure composed of multiple copies of ~30 proteins (nucleoporins, Nups) arranged into distinct subcomplexes [, ]. A number of these peptides are synthesised as precursors and undergo self-catalyzed cleavage. The largest NPC sub-complex is the heptameric Y-shaped mammalian Nup107-Nup160 complex (called Nup84 complex in budding yeast), an essential scaffolding component of the NPC [, , ]. Nup98 and Nup96 are encoded by the same gene that produces a 190 kDa polyprotein with autoproteolytic activity which generates the N-terminal NUP98 and C-terminal NUP96 proteins, part of the Nup107-Nup160 subcomplex [, ]. The yeast homologue Nup145 undergoes the similar proteolytic event to produce Nup145N and Nup145C, which are part of the Nup84 complex. The function of the heptamer is to coat the curvature of the nuclear pore complex between the inner and outer nuclear membranes. Nup96, which is predicted to be an alpha helical solenoid, complexes with Sec13 in the middle of the heptamer. The interaction between Nup96 and Sec13 is the point of curvature in the heptameric complex [, ].The proteolytic cleavage site of yeast Nup145p has been mapped upstream of an evolutionary conserved serine residue. Then, Nup145C form the heptameric Y-complex together with six other proteins while Nup145N shuttle between the NPC and the nuclear interior. [, ].Nup98,a component of the nuclear pore that plays its primary role in the export of RNAs, is expressed in two forms, derived from alternate mRNA splicing. Both forms are processed into two peptides through autoproteolysis mediated by the C-terminal domain of hNup98. The three-dimensional structure of the C-terminal domain reveals a novel protein fold, and thus a new class of autocatalytic proteases. The structure further reveals that the suggested nucleoporin RNA binding motif is unlikely to bind to RNA [].The following nucleoporins share an ~150-residue C-terminal domain responsible for NPC targeting [, ]:Vertebrate Nup98, a component of the nuclear pore that plays its primary role in the export of RNAs.Yeast Nup100, plays an important role in several nuclear export and import pathways including poly(A)+ RNA and protein transport.Yeast Nup116, involved in mRNA export and protein transport.Yeast Nup145, involved in nuclear poly(A)+ RNA and tRNA export.The NUP C-terminal domains of Nup98 and Nup145 possess peptidase S59autoproteolytic activity. The autoproteolytic sites of Nup98 and Nup145each occur immediately C-terminal to the NUP C-terminal domain. Thus, althoughthis domain occurs in the middle of each precursor polypeptide, it winds up atthe C-terminal end of the N-terminal cleavage product. Cleavage of the peptidechains are necessary for the proper targeting to the nuclear pore [, ].The NUP C-terminal domain adopts a predominantly β-strand structure. The molecule consists of a six-stranded β-sheet sandwiched against a two-stranded β-sheet and flanked by α-helical regions. The N-terminalhelical region consists of two short helices, whereas the stretch on the opposite side of molecule consists of a single, longer helix [, ].
Nuclear pore complexes (NPCs) facilitate all nucleocytoplasmic transport in eukaryotic cells, playing essential roles in cellular homeostasis. The NPC is a modular structure composed of multiple copies of ~30 proteins (nucleoporins, Nups) arranged into distinct subcomplexes [, ]. A number of these peptides are synthesised as precursors and undergo self-catalyzed cleavage. The largest NPC sub-complex is the heptameric Y-shaped mammalian Nup107-Nup160 complex (called Nup84 complex in budding yeast), an essential scaffolding component of the NPC [, , ]. Nup98 and Nup96 are encoded by the same gene that produces a 190 kDa polyprotein with autoproteolytic activity which generates the N-terminal NUP98 and C-terminal NUP96 proteins, part of the Nup107-Nup160 subcomplex [, ]. The yeast homologue Nup145 undergoes the similar proteolytic event to produce Nup145N and Nup145C, which are part of the Nup84 complex. The function of the heptamer is to coat the curvature of the nuclear pore complex between the inner and outer nuclear membranes. Nup96, which is predicted to be an alpha helical solenoid, complexes with Sec13 in the middle of the heptamer. The interaction between Nup96 and Sec13 is the point of curvature in the heptameric complex [, ].The proteolytic cleavage site of yeast Nup145p has been mapped upstream of an evolutionary conserved serine residue. Then, Nup145C form the heptameric Y-complex together with six other proteins while Nup145N shuttle between the NPC and the nuclear interior. [, ].Nup98, a component of the nuclear pore that plays its primary role in the export of RNAs, is expressed in two forms, derived from alternate mRNA splicing. Both forms are processed into two peptides through autoproteolysis mediated by the C-terminal domain of hNup98. The three-dimensional structure of the C-terminal domain reveals a novel protein fold, and thus a new class of autocatalytic proteases. The structure further reveals that the suggested nucleoporin RNA binding motif is unlikely to bind to RNA [].The following nucleoporins share an ~150-residue C-terminal domain responsible for NPC targeting [, ]:Vertebrate Nup98, a component of the nuclear pore that plays its primary role in the export of RNAs.Yeast Nup100, plays an important role in several nuclear export and import pathways including poly(A)+ RNA and protein transport.Yeast Nup116, involved in mRNA export and protein transport.Yeast Nup145, involved in nuclear poly(A)+ RNA and tRNA export.The NUP C-terminal domains of Nup98 and Nup145 possess peptidase S59autoproteolytic activity. The autoproteolytic sites of Nup98 and Nup145each occur immediately C-terminal to the NUP C-terminal domain. Thus, althoughthis domain occurs in the middle of each precursor polypeptide, it winds up atthe C-terminal end of the N-terminal cleavage product. Cleavage of the peptidechains are necessary for the proper targeting to the nuclear pore [, ].The NUP C-terminal domain adopts a predominantly β-strand structure. The molecule consists of a six-stranded β-sheet sandwiched against a two-stranded β-sheet and flanked by α-helical regions. The N-terminal helical region consists of two short helices, whereas the stretch on the opposite side of molecule consists of a single, longer helix [, ].
