| Structural highlights
6i5j is a 10 chain structure with sequence from Human. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
| | Ligands: | |
| NonStd Res: | , , |
| Gene: | SOCS2, CIS2, SSI2, STATI2 (HUMAN), ELOB, TCEB2 (HUMAN), ELOC, TCEB1 (HUMAN) |
| Resources: | FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT |
Function
[SOCS2_HUMAN] SOCS family proteins form part of a classical negative feedback system that regulates cytokine signal transduction. SOCS2 appears to be a negative regulator in the growth hormone/IGF1 signaling pathway. Probable substrate recognition component of a SCF-like ECS (Elongin BC-CUL2/5-SOCS-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. [ELOC_HUMAN] SIII, also known as elongin, is a general transcription elongation factor that increases the RNA polymerase II transcription elongation past template-encoded arresting sites. Subunit A is transcriptionally active and its transcription activity is strongly enhanced by binding to the dimeric complex of the SIII regulatory subunits B and C (elongin BC complex).[1] The elongin BC complex seems to be involved as an adapter protein in the proteasomal degradation of target proteins via different E3 ubiquitin ligase complexes, including the von Hippel-Lindau ubiquitination complex CBC(VHL). By binding to BC-box motifs it seems to link target recruitment subunits, like VHL and members of the SOCS box family, to Cullin/RBX1 modules that activate E2 ubiquitination enzymes.[2] [ELOB_HUMAN] SIII, also known as elongin, is a general transcription elongation factor that increases the RNA polymerase II transcription elongation past template-encoded arresting sites. Subunit A is transcriptionally active and its transcription activity is strongly enhanced by binding to the dimeric complex of the SIII regulatory subunits B and C (elongin BC complex).[3] [4] The elongin BC complex seems to be involved as an adapter protein in the proteasomal degradation of target proteins via different E3 ubiquitin ligase complexes, including the von Hippel-Lindau ubiquitination complex CBC(VHL). By binding to BC-box motifs it seems to link target recruitment subunits, like VHL and members of the SOCS box family, to Cullin/RBX1 modules that activate E2 ubiquitination enzymes.[5] [6]
Publication Abstract from PubMed
The suppressor of cytokine signaling 2 (SOCS2) acts as substrate recognition subunit of a Cullin5 E3 ubiquitin ligase complex. SOCS2 binds to phosphotyrosine-modified epitopes as degrons for ubiquitination and proteasomal degradation, yet the molecular basis of substrate recognition has remained elusive. Here, we report co-crystal structures of SOCS2-ElonginB-ElonginC in complex with phosphorylated peptides from substrates growth hormone receptor (GHR-pY595) and erythropoietin receptor (EpoR-pY426) at 1.98 A and 2.69 A, respectively. Both peptides bind in an extended conformation recapitulating the canonical SH2 domain-pY pose, but capture different conformations of the EF loop via specific hydrophobic interactions. The flexible BG loop is fully defined in the electron density, and does not contact the substrate degron directly. Cancer-associated SNPs located around the pY pocket weaken substrate-binding affinity in biophysical assays. Our findings reveal insights into substrate recognition and specificity by SOCS2, and provide a blueprint for small molecule ligand design.
Structural insights into substrate recognition by the SOCS2 E3 ubiquitin ligase.,Kung WW, Ramachandran S, Makukhin N, Bruno E, Ciulli A Nat Commun. 2019 Jun 10;10(1):2534. doi: 10.1038/s41467-019-10190-4. PMID:31182716[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Kario E, Marmor MD, Adamsky K, Citri A, Amit I, Amariglio N, Rechavi G, Yarden Y. Suppressors of cytokine signaling 4 and 5 regulate epidermal growth factor receptor signaling. J Biol Chem. 2005 Feb 25;280(8):7038-48. Epub 2004 Dec 7. PMID:15590694 doi:10.1074/jbc.M408575200
- ↑ Kario E, Marmor MD, Adamsky K, Citri A, Amit I, Amariglio N, Rechavi G, Yarden Y. Suppressors of cytokine signaling 4 and 5 regulate epidermal growth factor receptor signaling. J Biol Chem. 2005 Feb 25;280(8):7038-48. Epub 2004 Dec 7. PMID:15590694 doi:10.1074/jbc.M408575200
- ↑ Garrett KP, Aso T, Bradsher JN, Foundling SI, Lane WS, Conaway RC, Conaway JW. Positive regulation of general transcription factor SIII by a tailed ubiquitin homolog. Proc Natl Acad Sci U S A. 1995 Aug 1;92(16):7172-6. PMID:7638163
- ↑ Kario E, Marmor MD, Adamsky K, Citri A, Amit I, Amariglio N, Rechavi G, Yarden Y. Suppressors of cytokine signaling 4 and 5 regulate epidermal growth factor receptor signaling. J Biol Chem. 2005 Feb 25;280(8):7038-48. Epub 2004 Dec 7. PMID:15590694 doi:10.1074/jbc.M408575200
- ↑ Garrett KP, Aso T, Bradsher JN, Foundling SI, Lane WS, Conaway RC, Conaway JW. Positive regulation of general transcription factor SIII by a tailed ubiquitin homolog. Proc Natl Acad Sci U S A. 1995 Aug 1;92(16):7172-6. PMID:7638163
- ↑ Kario E, Marmor MD, Adamsky K, Citri A, Amit I, Amariglio N, Rechavi G, Yarden Y. Suppressors of cytokine signaling 4 and 5 regulate epidermal growth factor receptor signaling. J Biol Chem. 2005 Feb 25;280(8):7038-48. Epub 2004 Dec 7. PMID:15590694 doi:10.1074/jbc.M408575200
- ↑ Kung WW, Ramachandran S, Makukhin N, Bruno E, Ciulli A. Structural insights into substrate recognition by the SOCS2 E3 ubiquitin ligase. Nat Commun. 2019 Jun 10;10(1):2534. doi: 10.1038/s41467-019-10190-4. PMID:31182716 doi:http://dx.doi.org/10.1038/s41467-019-10190-4
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