6jpv
Structural analysis of AIMP2-DX2 and HSP70 interaction
Structural highlights
FunctionAIMP2_HUMAN Required for assembly and stability of the aminoacyl-tRNA synthase complex. Mediates ubiquitination and degradation of FUBP1, a transcriptional activator of MYC, leading to MYC down-regulation which is required for aveolar type II cell differentiation. Blocks MDM2-mediated ubiquitination and degradation of p53/TP53. Functions as a proapoptotic factor.[1] HS71A_HUMAN In cooperation with other chaperones, Hsp70s stabilize preexistent proteins against aggregation and mediate the folding of newly translated polypeptides in the cytosol as well as within organelles. These chaperones participate in all these processes through their ability to recognize nonnative conformations of other proteins. They bind extended peptide segments with a net hydrophobic character exposed by polypeptides during translation and membrane translocation, or following stress-induced damage. In case of rotavirus A infection, serves as a post-attachment receptor for the virus to facilitate entry into the cell. Essential for STUB1-mediated ubiquitination and degradation of FOXP3 in regulatory T-cells (Treg) during inflammation (PubMed:23973223).[2] [3] [4] Publication Abstract from PubMedA tumorigenic factor, AIMP2 lacking exon 2 (AIMP2-DX2), is often upregulated in many cancers. However, how its cellular level is determined is not understood. Here, we report heat-shock protein HSP70 as a critical determinant for the level of AIMP2-DX2. Interaction of the two factors was identified by interactome analysis and structurally determined by X-ray crystallography and NMR analyses. HSP70 recognizes the amino (N)-terminal flexible region, as well as the glutathione S-transferase domain of AIMP2-DX2, via its substrate-binding domain, thus blocking the Siah1-dependent ubiquitination of AIMP2-DX2. AIMP2-DX2-induced cell transformation and cancer progression in vivo was further augmented by HSP70. A positive correlation between HSP70 and AIMP2-DX2 levels was shown in various lung cancer cell lines and patient tissues. Chemical intervention in the AIMP2-DX2-HSP70 interaction suppressed cancer cell growth in vitro and in vivo. Thus, this work demonstrates the importance of the interaction between AIMP2-DX2 and HSP70 on tumor progression and its therapeutic potential against cancer. Targeting the interaction of AIMP2-DX2 with HSP70 suppresses cancer development.,Lim S, Cho HY, Kim DG, Roh Y, Son SY, Mushtaq AU, Kim M, Bhattarai D, Sivaraman A, Lee Y, Lee J, Yang WS, Kim HK, Kim MH, Lee K, Jeon YH, Kim S Nat Chem Biol. 2020 Jan;16(1):31-41. doi: 10.1038/s41589-019-0415-2. Epub 2019, Dec 2. PMID:31792442[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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