Journal: Nature / Year: 2021 Title: AKIRIN2 controls the nuclear import of proteasomes in vertebrates. Authors: Melanie de Almeida / Matthias Hinterndorfer / Hanna Brunner / Irina Grishkovskaya / Kashish Singh / Alexander Schleiffer / Julian Jude / Sumit Deswal / Robert Kalis / Milica Vunjak / Thomas ...Authors: Melanie de Almeida / Matthias Hinterndorfer / Hanna Brunner / Irina Grishkovskaya / Kashish Singh / Alexander Schleiffer / Julian Jude / Sumit Deswal / Robert Kalis / Milica Vunjak / Thomas Lendl / Richard Imre / Elisabeth Roitinger / Tobias Neumann / Susanne Kandolf / Michael Schutzbier / Karl Mechtler / Gijs A Versteeg / David Haselbach / Johannes Zuber / Abstract: Protein expression and turnover are controlled through a complex interplay of transcriptional, post-transcriptional and post-translational mechanisms to enable spatial and temporal regulation of ...Protein expression and turnover are controlled through a complex interplay of transcriptional, post-transcriptional and post-translational mechanisms to enable spatial and temporal regulation of cellular processes. To systematically elucidate such gene regulatory networks, we developed a CRISPR screening assay based on time-controlled Cas9 mutagenesis, intracellular immunostaining and fluorescence-activated cell sorting that enables the identification of regulatory factors independent of their effects on cellular fitness. We pioneered this approach by systematically probing the regulation of the transcription factor MYC, a master regulator of cell growth. Our screens uncover a highly conserved protein, AKIRIN2, that is essentially required for nuclear protein degradation. We found that AKIRIN2 forms homodimers that directly bind to fully assembled 20S proteasomes to mediate their nuclear import. During mitosis, proteasomes are excluded from condensing chromatin and re-imported into newly formed daughter nuclei in a highly dynamic, AKIRIN2-dependent process. Cells undergoing mitosis in the absence of AKIRIN2 become devoid of nuclear proteasomes, rapidly causing accumulation of MYC and other nuclear proteins. Collectively, our study reveals a dedicated pathway controlling the nuclear import of proteasomes in vertebrates and establishes a scalable approach to decipher regulators in essential cellular processes.
History
Deposition
Aug 21, 2020
-
Header (metadata) release
Sep 1, 2021
-
Map release
Sep 1, 2021
-
Update
Dec 1, 2021
-
Current status
Dec 1, 2021
Processing site: PDBe / Status: Released
-
Structure visualization
Movie
Surface view with section colored by density value
Download / File: emd_11649.map.gz / Format: CCP4 / Size: 103 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES)
Voxel size
X=Y=Z: 1.85 Å
Density
Contour Level
By AUTHOR: 0.0029 / Movie #1: 0.0029
Minimum - Maximum
-0.042500027 - 0.041203734
Average (Standard dev.)
-3.4781406e-05 (±0.0025890071)
Symmetry
Space group: 1
Details
EMDB XML:
Map geometry
Axis order
X
Y
Z
Origin
0
0
0
Dimensions
300
300
300
Spacing
300
300
300
Cell
A=B=C: 555.0 Å α=β=γ: 90.0 °
CCP4 map header:
mode
Image stored as Reals
Å/pix. X/Y/Z
1.85
1.85
1.85
M x/y/z
300
300
300
origin x/y/z
0.000
0.000
0.000
length x/y/z
555.000
555.000
555.000
α/β/γ
90.000
90.000
90.000
MAP C/R/S
1
2
3
start NC/NR/NS
0
0
0
NC/NR/NS
300
300
300
D min/max/mean
-0.043
0.041
-0.000
-
Supplemental data
-
Sample components
-
Entire : Akirin2 bound to the human 26S proteasome
Entire
Name: Akirin2 bound to the human 26S proteasome
Components
Complex: Akirin2 bound to the human 26S proteasome
-
Supramolecule #1: Akirin2 bound to the human 26S proteasome
Supramolecule
Name: Akirin2 bound to the human 26S proteasome / type: complex / ID: 1 / Parent: 0
Source (natural)
Organism: Homo sapiens (human)
Recombinant expression
Organism: Escherichia coli (E. coli)
-
Experimental details
-
Structure determination
Method
negative staining
Processing
single particle reconstruction
Aggregation state
particle
-
Sample preparation
Buffer
pH: 6.5
Staining
Type: NEGATIVE / Material: Uranyl Acetate
Grid
Model: Homemade / Support film - Material: CARBON / Support film - topology: CONTINUOUS / Support film - Film thickness: 2.0 nm / Pretreatment - Type: GLOW DISCHARGE / Pretreatment - Atmosphere: AIR
-
Electron microscopy
Microscope
FEI TECNAI 20
Image recording
Film or detector model: FEI EAGLE (2k x 2k) / Average electron dose: 60.0 e/Å2
Electron beam
Acceleration voltage: 200 kV / Electron source: LAB6
Electron optics
C2 aperture diameter: 100.0 µm / Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.0 mm
-
Image processing
Final reconstruction
Applied symmetry - Point group: C1 (asymmetric) / Resolution.type: BY AUTHOR / Resolution: 21.0 Å / Resolution method: FSC 0.5 CUT-OFF / Software - Name: RELION (ver. 3.1) / Number images used: 36000
Initial angle assignment
Type: RANDOM ASSIGNMENT / Software - Name: RELION (ver. 3.1)
In the structure databanks used in Yorodumi, some data are registered as the other names, "COVID-19 virus" and "2019-nCoV". Here are the details of the virus and the list of structure data.
Jan 31, 2019. EMDB accession codes are about to change! (news from PDBe EMDB page)
EMDB accession codes are about to change! (news from PDBe EMDB page)
The allocation of 4 digits for EMDB accession codes will soon come to an end. Whilst these codes will remain in use, new EMDB accession codes will include an additional digit and will expand incrementally as the available range of codes is exhausted. The current 4-digit format prefixed with “EMD-” (i.e. EMD-XXXX) will advance to a 5-digit format (i.e. EMD-XXXXX), and so on. It is currently estimated that the 4-digit codes will be depleted around Spring 2019, at which point the 5-digit format will come into force.
The EM Navigator/Yorodumi systems omit the EMD- prefix.
Related info.:Q: What is EMD? / ID/Accession-code notation in Yorodumi/EM Navigator
Yorodumi is a browser for structure data from EMDB, PDB, SASBDB, etc.
This page is also the successor to EM Navigator detail page, and also detail information page/front-end page for Omokage search.
The word "yorodu" (or yorozu) is an old Japanese word meaning "ten thousand". "mi" (miru) is to see.
Related info.:EMDB / PDB / SASBDB / Comparison of 3 databanks / Yorodumi Search / Aug 31, 2016. New EM Navigator & Yorodumi / Yorodumi Papers / Jmol/JSmol / Function and homology information / Changes in new EM Navigator and Yorodumi