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Open data
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Basic information
| Entry | ![]() | ||||||||||||
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| Title | Autoinhibited P-Rex2 Composite Map | ||||||||||||
Map data | Composite map for whole particle | ||||||||||||
Sample |
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Keywords | Rho guanine-nucleotide exchange factor / autoinhibition / SIGNALING PROTEIN | ||||||||||||
| Function / homology | Function and homology informationnegative regulation of TOR signaling / regulation of small GTPase mediated signal transduction / CDC42 GTPase cycle / RHOA GTPase cycle / protein serine/threonine kinase inhibitor activity / RAC1 GTPase cycle / guanyl-nucleotide exchange factor activity / GTPase activator activity / Regulation of PTEN stability and activity / intracellular signal transduction ...negative regulation of TOR signaling / regulation of small GTPase mediated signal transduction / CDC42 GTPase cycle / RHOA GTPase cycle / protein serine/threonine kinase inhibitor activity / RAC1 GTPase cycle / guanyl-nucleotide exchange factor activity / GTPase activator activity / Regulation of PTEN stability and activity / intracellular signal transduction / G protein-coupled receptor signaling pathway / plasma membrane / cytosol Similarity search - Function | ||||||||||||
| Biological species | Homo sapiens (human) | ||||||||||||
| Method | single particle reconstruction / cryo EM / Resolution: 5.2 Å | ||||||||||||
Authors | Anderson LK / Cash JN | ||||||||||||
| Funding support | United States, 3 items
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Citation | Journal: J Biol Chem / Year: 2026Title: The Rho guanine-nucleotide exchange factor P-Rex2 exhibits structural and regulatory features distinct from the related RhoGEF P-Rex1. Authors: Lauren K Anderson / Rohan Marde / Grace Muma / Veda Nayak / Chi Phan / Sheng Li / Jennifer N Cash / ![]() Abstract: Rho guanine-nucleotide exchange factors (RhoGEFs) activate small GTPases to drive cytoskeletal rearrangement, cell motility, and proliferation. The phosphatidylinositol-3,4,5-trisphosphate (PIP)- ...Rho guanine-nucleotide exchange factors (RhoGEFs) activate small GTPases to drive cytoskeletal rearrangement, cell motility, and proliferation. The phosphatidylinositol-3,4,5-trisphosphate (PIP)-dependent Rac exchanger (P-Rex) subfamily of RhoGEFs includes P-Rex1 and P-Rex2 which, when misregulated, contribute to cancer progression and metastasis. P-Rex activity is controlled by accessory domains that maintain the protein in a cytosolic, autoinhibited state until activated by the lipid PIP and G protein βγ subunits. While P-Rex1 autoinhibition has been structurally and biochemically characterized, P-Rex2 has remained largely unexplored. Furthermore, despite high sequence similarity and domain conservation, P-Rex homologs differ in substrate specificity and regulatory interactions, and the molecular basis for these divergences is unknown. Here, we have taken an integrative structural biology approach to investigate these gaps. Using cryo-EM, we determined the first structure of full-length P-Rex2 to moderate resolution, revealing that, while the overall structure closely resembles that of P-Rex1, there is a substantial repositioning of the N-terminal module relative to the C-terminal core. This may play a key role in precluding the intramolecular interactions between the N- and C-terminal domains that are observed in autoinhibited P-Rex1. Hydrogen-deuterium exchange mass spectrometry revealed that, unlike P-Rex1, P-Rex2 dynamics are unaffected by IP, the headgroup of PIP. SEC-SAXS data support that the N-terminal module itself is less dynamic, and biochemical assays show that P-Rex2 may be differently regulated by autoinhibition, likely through a mechanism divergent from P-Rex1. These findings uncover unique features in the molecular mechanisms of P-Rex2 regulation. | ||||||||||||
| History |
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Structure visualization
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Downloads & links
-EMDB archive
| Map data | emd_74550.map.gz | 274.1 MB | EMDB map data format | |
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| Header (meta data) | emd-74550-v30.xml emd-74550.xml | 17.8 KB 17.8 KB | Display Display | EMDB header |
| Images | emd_74550.png | 84.3 KB | ||
| Filedesc metadata | emd-74550.cif.gz | 7.4 KB | ||
| Archive directory | http://ftp.pdbj.org/pub/emdb/structures/EMD-74550 ftp://ftp.pdbj.org/pub/emdb/structures/EMD-74550 | HTTPS FTP |
-Related structure data
| Related structure data | ![]() 9zq7MC C: citing same article ( M: atomic model generated by this map |
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| Similar structure data | Similarity search - Function & homology F&H Search |
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Links
| EMDB pages | EMDB (EBI/PDBe) / EMDataResource |
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| Related items in Molecule of the Month |
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Map
| File | Download / File: emd_74550.map.gz / Format: CCP4 / Size: 343 MB / Type: IMAGE STORED AS FLOATING POINT NUMBER (4 BYTES) | ||||||||||||||||||||||||||||||||||||
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| Annotation | Composite map for whole particle | ||||||||||||||||||||||||||||||||||||
| Projections & slices | Image control
Images are generated by Spider. | ||||||||||||||||||||||||||||||||||||
| Voxel size | X=Y=Z: 0.7296 Å | ||||||||||||||||||||||||||||||||||||
| Density |
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| Symmetry | Space group: 1 | ||||||||||||||||||||||||||||||||||||
| Details | EMDB XML:
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-Supplemental data
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Sample components
-Entire : Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger ...
| Entire | Name: Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 2 (P-Rex2) |
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| Components |
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-Supramolecule #1: Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger ...
| Supramolecule | Name: Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 2 (P-Rex2) type: organelle_or_cellular_component / ID: 1 / Parent: 0 / Macromolecule list: all |
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| Source (natural) | Organism: Homo sapiens (human) |
| Molecular weight | Theoretical: 183 KDa |
-Macromolecule #1: Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger ...
| Macromolecule | Name: Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 2 protein type: protein_or_peptide / ID: 1 / Number of copies: 1 / Enantiomer: LEVO |
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| Source (natural) | Organism: Homo sapiens (human) |
| Molecular weight | Theoretical: 184.506203 KDa |
| Recombinant expression | Organism: Homo sapiens (human) |
| Sequence | String: GAMDPMSEDS RGDSRAESAK DLEKQLRLRV CVLSELQKTE RDYVGTLEFL VSAFLHRMNQ CAASKVDKNV TEETVKMLFS NIEDILAVH KEFLKVVEEC LHPEPNAQQE VGTCFLHFKD KFRIYDEYCS NHEKAQKLLL ELNKIRTIRT FLLNCMLLGG R KNTDVPLE ...String: GAMDPMSEDS RGDSRAESAK DLEKQLRLRV CVLSELQKTE RDYVGTLEFL VSAFLHRMNQ CAASKVDKNV TEETVKMLFS NIEDILAVH KEFLKVVEEC LHPEPNAQQE VGTCFLHFKD KFRIYDEYCS NHEKAQKLLL ELNKIRTIRT FLLNCMLLGG R KNTDVPLE GYLVTPIQRI CKYPLILKEL LKRTPRKHSD YAAVMEALQA MKAVCSNINE AKRQMEKLEV LEEWQSHIEG WE GSNITDT CTEMLMCGVL LKISSGNIQE RVFFLFDNLL VYCKRKHRRL KNSKASTDGH RYLFRGRINT EVMEVENVDD GTA DFHSSG HIVVNGWKIH NTAKNKWFVC MAKTPEEKHE WFEAILKERE RRKGLKLGME QDTWVMISEQ GEKLYKMMCR QGNL IKDRK RKLTTFPKCF LGSEFVSWLL EIGEIHRPEE GVHLGQALLE NGIIHHVTDK HQFKPEQMLY RFRYDDGTFY PRNEM QDVI SKGVRLYCRL HSLFTPVIRD KDYHLRTYKS VVMANKLIDW LIAQGDCRTR EEAMIFGVGL CDNGFMHHVL EKSEFK DEP LLFRFFSDEE MEGSNMKHRL MKHDLKVVEN VIAKSLLIKS NEGSYGFGLE DKNKVPIIKL VEKGSNAEMA GMEVGKK IF AINGDLVFMR PFNEVDCFLK SCLNSRKPLR VLVSTKPRET VKIPDSADGL GFQIRGFGPS VVHAVGRGTV AAAAGLHP G QCIIKVNGIN VSKETHASVI AHVTACRKYR RPTKQDSIQW VYNSIESAQE DLQKSHSKPP GDEAGDAFDC KVEEVIDKF NTMAIIDGKK EHVSLTVDNV HLEYGVVYEY DSTAGIKCNV VEKMIEPKGF FSLTAKILEA LAKSDEHFVQ NCTSLNSLNE VIPTDLQSK FSALCSERIE HLCQRISSYK KFSRVLKNRA WPTFKQAKSK ISPLHSSDFC PTNCHVNVME VSYPKTSTSL G SAFGVQLD SRKHNSHDKE NKSSEQGKLS PMVYIQHTIT TMAAPSGLSL GQQDGHGLRY LLKEEDLETQ DIYQKLLGKL QT ALKEVEM CVCQIDDLLS SITYSPKLER KTSEGIIPTD SDNEKGERNS KRVCFNVAGD EQEDSGHDTI SNRDSYSDCN SNR NSIASF TSICSSQCSS YFHSDEMDSG DELPLSVRIS HDKQDKIHSC LEHLFSQVDS ITNLLKGQAV VRAFDQTKYL TPGR GLQEF QQEMEPKLSC PKRLRLHIKQ DPWNLPSSVR TLAQNIRKFV EEVKCRLLLA LLEYSDSETQ LRRDMVFCQT LVATV CAFS EQLMAALNQM FDNSKENEME TWEASRRWLD QIANAGVLFH FQSLLSPNLT DEQAMLEDTL VALFDLEKVS FYFKPS EEE PLVANVPLTY QAEGSRQALK VYFYIDSYHF EQLPQRLKNG GGFKIHPVLF AQALESMEGY YYRDNVSVEE FQAQINA AS LEKVKQYNQK LRAFYLDKSN SPPNSTSKAA YVDKLMRPLN ALDELYRLVA SFIRSKRTAA CANTACSASG VGLLSVSS E LCNRLGACHI IMCSSGVHRC TLSVTLEQAI ILARSHGLPP RYIMQATDVM RKQGARVQNT AKNLGVRDRT PQSAPRLYK LCEPPPPAGE EPGDYKDDDD K UniProtKB: Phosphatidylinositol 3,4,5-trisphosphate-dependent Rac exchanger 2 protein |
-Experimental details
-Structure determination
| Method | cryo EM |
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Processing | single particle reconstruction |
| Aggregation state | particle |
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Sample preparation
| Concentration | 0.4 mg/mL |
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| Buffer | pH: 8 Details: 20 mM HEPES (pH 8.0), 100 mM NaCl, 2 mM dithiothreitol (DTT), 0.07 mM n-Dodecyl-B-D-Maltoside (DDM) |
| Grid | Model: Quantifoil R1.2/1.3 / Material: COPPER / Mesh: 300 / Support film - Material: CARBON / Support film - topology: HOLEY |
| Vitrification | Cryogen name: ETHANE / Chamber humidity: 100 % / Chamber temperature: 277.15 K |
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Electron microscopy
| Microscope | TFS KRIOS |
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| Specialist optics | Energy filter - Name: TFS Selectris X / Energy filter - Slit width: 10 eV |
| Image recording | Film or detector model: TFS FALCON 4i (4k x 4k) / Number grids imaged: 2 / Number real images: 19792 / Average electron dose: 50.0 e/Å2 Details: 12070 untilted micrographs and 7722 micrographs with 35 tilt |
| Electron beam | Acceleration voltage: 300 kV / Electron source: FIELD EMISSION GUN |
| Electron optics | Illumination mode: FLOOD BEAM / Imaging mode: BRIGHT FIELD / Cs: 2.7 mm / Nominal defocus max: 2.2 µm / Nominal defocus min: 0.7000000000000001 µm |
| Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Image processing
-Atomic model buiding 1
| Initial model |
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| Details | AlphaFold server used to generate individual initial models of the core and N-terminal module which were rigid body fit to the composite map and further refined in Coot. | ||||||
| Refinement | Protocol: RIGID BODY FIT | ||||||
| Output model | ![]() PDB-9zq7: |
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Keywords
Homo sapiens (human)
Authors
United States, 3 items
Citation







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Y (Row.)
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FIELD EMISSION GUN
