The structure and flexibility analysis of the Arabidopsis synaptotagmin 1 reveal the basis of its regulation at membrane contact sites

DOI: 10.26508/lsa.202101152

Authors: Juan L Benavente (Instituto de Química Física “Rocasolano,” Consejo Superior de Investigaciones Científicas (CSIC)) , Dritan Siliqi (Istituto di Cristallografia, Consiglio Nazionale delle Ricerche (CNR)) , Lourdes Infantes (Instituto de Química Física “Rocasolano,” Consejo Superior de Investigaciones Científicas (CSIC)) , Laura Lagartera (Instituto de Química Médica (IQM), CSIC) , Alberto Mills (Unidad Asociada al IQM-CSIC, Universidad de Alcalá) , Federico Gago (Unidad Asociada al IQM-CSIC, Universidad de Alcalá) , Noemí Ruiz-López (Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-CSIC (IHSM-UMA-CSIC), Universidad de Málaga) , Miguel A Botella (Instituto de Hortofruticultura Subtropical y Mediterránea “La Mayora,” Universidad de Málaga-CSIC (IHSM-UMA-CSIC), Universidad de Málaga) , Maria J. Sanchez-Barrena (Instituto de Química Física “Rocasolano,” Consejo Superior de Investigaciones Científicas (CSIC)) , Armando Albert (Instituto de Química Física “Rocasolano,” Consejo Superior de Investigaciones Científicas (CSIC))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Life Science Alliance , VOL 4

State: Published (Approved)
Published: August 2021
Diamond Proposal Number(s): 21741

Abstract: Non-vesicular lipid transfer at ER and plasma membrane (PM) contact sites (CS) is crucial for the maintenance of membrane lipid homeostasis. Extended synaptotagmins (E-Syts) play a central role in this process as they act as molecular tethers of ER and PM and as lipid transfer proteins between these organelles. E-Syts are proteins constitutively anchored to the ER through an N-terminal hydrophobic segment and bind the PM via a variable number of C-terminal C2 domains. Synaptotagmins (SYTs) are the plant orthologous of E-Syts and regulate the ER–PM communica- tion in response to abiotic stress. Combining different structural and biochemical techniques, we demonstrate that the binding of SYT1 to lipids occurs through a Ca2+-dependent lipid-binding site and by a site for phosphorylated forms of phosphatidylinositol, thus integrating two different molecular signals in response to stress. In addition, we show that SYT1 displays three highly flexible hinge points that provide conformational freedom to facilitate lipid extraction, protein loading, and subsequent transfer between PM and ER.

Subject Areas: Medicine, Biology and Bio-materials


Instruments: B21-High Throughput SAXS

Other Facilities: XALOC at ALBA

Added On: 27/09/2021 08:16

Documents:
e202101152.full.pdf

Discipline Tags:

Plant science Structural biology Life Sciences & Biotech

Technical Tags:

Scattering Small Angle X-ray Scattering (SAXS)