Calmodulin binds to the STAS domain of SLC26A5 prestin with a calcium-dependent, one-lobe, binding mode
| Autor: | Antonio Macchiarulo, Roberto Battistutta, Alice Coletti, Barbara Zambelli, Massimo Bellanda, Elisa Costanzi |
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| Přispěvatelé: | Costanzi E., Coletti A., Zambelli B., Macchiarulo A., Bellanda M., Battistutta R. |
| Rok vydání: | 2020 |
| Předmět: |
Small Angle
Magnetic Resonance Spectroscopy Calmodulin Protein Conformation Protein–protein interaction Scattering 03 medical and health sciences Hearing Protein Domains X-Ray Diffraction Structural Biology Scattering Small Angle Animals STAS domain Prestin 030304 developmental biology 0303 health sciences Biophysical methods Chromatography Gel Binding Sites biology Chemistry Protein interaction Circular Dichroism 030302 biochemistry & molecular biology Protein interactions Transporter Low-resolution model Biophysical method Cytosol Transmembrane domain Sulfate Transporters biology.protein Biophysics Chromatography Gel Calcium sense organs Chickens Intracellular Function (biology) |
| Zdroj: | Journal of structural biology. 213(2) |
| ISSN: | 1095-8657 |
| Popis: | SLC26A5 transporter prestin is fundamental for the higher hearing sensitivity and frequency selectivity of mammals. Prestin is a voltage-dependent transporter found in the cochlear outer hair cells responsible for their electromotility. Intracellular chloride binding is considered essential for voltage sensitivity and electromotility. Prestin is composed by a transmembrane domain and by a cytosolic domain called STAS. There is evidence of a calcium/calmodulin regulation of prestin mediated by the STAS domain. Using different biophysical techniques, namely SEC, CD, ITC, MST, NMR and SAXS, here we demonstrate and characterize the direct interaction between calmodulin and prestin STAS. We show that the interaction is calcium-dependent and that involves residues at the N-terminal end of the "variable loop". This is an intrinsically disordered insertion typical of the STAS domains of the SLC26 family of transporters whose function is still unclear. We derive a low-resolution model of the STAS/CaM complex, where only one lobe of calmodulin is engaged in the interaction, and build a model for the entire dimeric prestin in complex with CaM, which can use the unoccupied lobe to interact with other regions of prestin or with other regulatory proteins. We show that also a non-mammalian STAS can interact with calmodulin via the variable loop. These data start to shed light on the regulatory role of the STAS variable loop of prestin. |
| Databáze: | OpenAIRE |
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