KRAS Prenylation Is Required for Bivalent Binding with Calmodulin in a Nucleotide-Independent Manner
| العنوان: | KRAS Prenylation Is Required for Bivalent Binding with Calmodulin in a Nucleotide-Independent Manner |
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| المؤلفون: | Marco Tonelli, Simon Messing, Frank McCormick, Lakshman Bindu, Rodolfo Ghirlando, Constance Agamasu, Dwight V. Nissley, Troy Taylor, Andrew G. Stephen, Timothy H. Tran |
| المصدر: | Biophysical journal, vol 116, iss 6 Biophysical Journal |
| بيانات النشر: | Elsevier BV, 2019. |
| سنة النشر: | 2019 |
| مصطلحات موضوعية: | Models, Molecular, Calmodulin, Amino Acid Motifs, Protein Prenylation, Biophysics, Plasma protein binding, Proto-Oncogene Proteins p21(ras), 03 medical and health sciences, 0302 clinical medicine, Prenylation, Models, Humans, Amino Acid Sequence, Protein kinase A, 030304 developmental biology, 0303 health sciences, biology, Nucleotides, Chemistry, Molecular, Articles, Biological Sciences, Cell biology, Docking (molecular), Physical Sciences, Chemical Sciences, biology.protein, Protein prenylation, Generic health relevance, Signal transduction, 030217 neurology & neurosurgery, Protein Binding, Cysteine |
| الوصف: | Deregulation of KRAS4b signaling pathway has been implicated in 30% of all cancers. Membrane localization of KRAS4b is an essential step for the initiation of the downstream signaling cascades that guide various cellular mechanisms. KRAS4b plasma membrane (PM) binding is mediated by the insertion of a prenylated moiety that is attached to the terminal carboxy-methylated cysteine, in addition to electrostatic interactions of its positively charged hypervariable region with anionic lipids. Calmodulin (CaM) has been suggested to selectively bind KRAS4b to act as a negative regulator of the RAS/mitogen-activated protein kinase (MAPK) signaling pathway by displacing KRAS4b from the membrane. However, the mechanism by which CaM can recognize and displace KRAS4b from the membrane is not well understood. In this study, we employed biophysical and structural techniques to characterize this mechanism in detail. We show that KRAS4b prenylation is required for bindingtoCaM and that the hydrophobic pockets of CaM can accommodate the prenylated region of KRAS4b, which might representa novel CaM-binding motif. Remarkably, prenylated KRAS4b forms a 2:1 stoichiometric complex with CaM in a nucleotide-independentmanner. The interaction between prenylated KRAS4b and CaM is enthalpically driven, and electrostatic interactions also contribute to the formation of the complex. The prenylated KRAS4b terminal KSKTKC-farnesylation and carboxy-methylation is sufficient for binding and defines the minimal CaM-binding motif. This is the same region implicated in membrane and phosphodiesterase6-δ binding. Finally, we provide a structure-based docking model by which CaM binds to prenylated KRAS4b. Our data provide new insights into the KRAS4b-CaM interaction and suggest a possible mechanism whereby CaM can regulate KRAS4b membrane localization. |
| وصف الملف: | application/pdf |
| تدمد: | 0006-3495 |
| الوصول الحر: | https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f98cb35a861aaec76539bd87a897c02dTest https://doi.org/10.1016/j.bpj.2019.02.004Test |
| حقوق: | OPEN |
| رقم الانضمام: | edsair.doi.dedup.....f98cb35a861aaec76539bd87a897c02d |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 00063495 |
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