1.I.1.1.1 Nuclear Pore Complex (NPC) (Tran and Wente, 2006). The structure of the NPC core (400kD) has been determined at 7.4 Å resolution revealing a curved Y-shaped architecture with the coat nucleoporin interactions forming the central ""triskeleton"". 32 copies of the coat neucloporin complex (CNC) structure dock into the cryoelectron tomographic reconstruction of the assembled human NPC, thus accounting for ~16 MDa of it's mass (Stuwe et al. 2015). Import of integral membrane proteins (mono- and polytopic) into the the inner nuclear membrane occurs by an active,
transport factor-dependent process (Laba et al. 2015). Ndc1 and Pom52 are partially redundant NPC components that are essential for proper assembly of the NPC. The absence of Ndc1p and Pom152p results in aberrant pores that have enlarged diameters and lack proteinaceous material, leading to increased diffusion between the cytoplasm and the nucleus (Madrid et al. 2006). Pom152 is a transmembrane protein within the nuclear pore complex (NPC) of fungi that is important for NPC assembly and structure. Pom152 is comprised of a short amino-terminal region that remains on the cytosolic side of the nuclear envelope (NE) and interacts with NPC proteins, a transmembrane domain, and a large, glycosylated carboxy-terminal domain within the NE lumen. Here we show that the N-terminal 200 amino acids of Pom152 that include only the amino-terminal and transmembrane regions are sufficient for localization to the NPC (Brown et al. 2021). Atg39 selectively captures the inner nuclear membrane into lumenal vesicles for delivery to the autophagosome (Chandra et al. 2021). The inner nuclear membrane (INM) changes its protein composition during gametogenesis, sheding light on mechanisms used to shape the INM proteome of spores (Shelton et al. 2021). Several nucleoporins with FG-repeats (phenylalanine-glycine repeats) (barrier nucleoporins) possess potential
amyloidogenic properties (Danilov et al. 2023). A multiscale structure of the yeast nuclear pore complex has been described, and its implications have been discussed (Akey et al. 2023). NPCs direct the nucleocytoplasmic transport of macromolecules, and Akey et al. 2023 provided a composite multiscale structure of the yeast NPC, based on improved 3D density maps from cryoEM and AlphaFold2 models. Key features of the inner and outer rings were integrated into a comprehensive model. The authors resolved flexible connectors that tie together the core scaffold, along with equatorial transmembrane complexes and a lumenal ring that anchor this channel within the pore membrane. The organization of the nuclear double outer ring revealed an architecture that may be shared with ancestral NPCs. Additional connections between the core scaffold and the central transporter suggest that under certain conditions, a degree of local organization is present at the periphery of the transport machinery. These connectors may couple conformational changes in the scaffold to the central transporter to modulate transport. Collectively, this analysis provides insights into assembly, transport, and NPC evolution (Akey et al. 2023).
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Accession Number: | Q06159 |
Protein Name: | Autophagy-related protein 39 |
Length: | 398 |
Molecular Weight: | 46628.00 |
Species: | Saccharomyces cerevisiae (strain ATCC 204508 / S288c) (Baker's yeast) [559292] |
Number of TMSs: | 1 |
Location1 / Topology2 / Orientation3: |
Endoplasmic reticulum membrane1 / Single-pass membrane protein2 |
Substrate |
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1: MSEEDDHWNL VRLRRLRKGR EGEEQSSKSE ISLDSLHESS FAGEDDEDFD ADVLSNTSSE
61: ESAQMNRIYD FRTSNEFSNA GVNIDQTGVP TISESFDTLS GSNVGGTVLP SMEGSKLKDS
121: TIRNSSTLSD HIIDKSEGKS AKLKMWHVIM LSSLLSMTFS YLALEYSLTG DVLAGFKSQQ
181: SLRNNERKLL YGNIDFVDKK SYDSSSDSLS QWAPSGKYYV DFDNHIAYPL KDDDLMGWRR
241: YKTDLVILWY TTKARMKDGW HKRINKINGG RIKLHLFLKN SFKSAQESLR VLHKEQKRRW
301: KRLFVLLHNK YRQFSPHIKR YFDHSCQKAK QCWSGSRLQL RKLRFKSMKP FRVFQFKVRK
361: DTNWFVKQLK RFGLKLQHSR MYKAMSECRK KNYFKCKH