scholarly journals The 2β Splice Variation Alters the Structure and Function of the Stromal Interaction Molecule Coiled-Coil Domains

2018 ◽  
Vol 19 (11) ◽  
pp. 3316 ◽  
Author(s):  
Steve Chung ◽  
MengQi Zhang ◽  
Peter Stathopulos

Stromal interaction molecule (STIM)-1 and -2 regulate agonist-induced and basal cytosolic calcium (Ca2+) levels after oligomerization and translocation to endoplasmic reticulum (ER)-plasma membrane (PM) junctions. At these junctions, the STIM cytosolic coiled-coil (CC) domains couple to PM Orai1 proteins and gate these Ca2+ release-activated Ca2+ (CRAC) channels, which facilitate store-operated Ca2+ entry (SOCE). Unlike STIM1 and STIM2, which are SOCE activators, the STIM2β splice variant contains an 8-residue insert located within the conserved CCs which inhibits SOCE. It remains unclear if the 2β insert further depotentiates weak STIM2 coupling to Orai1 or independently causes structural perturbations which prevent SOCE. Here, we use far-UV circular dichroism, light scattering, exposed hydrophobicity analysis, solution small angle X-ray scattering, and a chimeric STIM1/STIM2β functional assessment to provide insights into the molecular mechanism by which the 2β insert precludes SOCE activation. We find that the 2β insert reduces the overall α-helicity and enhances the exposed hydrophobicity of the STIM2 CC domains in the absence of a global conformational change. Remarkably, incorporation of the 2β insert into the STIM1 context not only affects the secondary structure and hydrophobicity as observed for STIM2, but also eliminates the more robust SOCE response mediated by STIM1. Collectively, our data show that the 2β insert directly precludes Orai1 channel activation by inducing structural perturbations in the STIM CC region.

2008 ◽  
Vol 190 (13) ◽  
pp. 4749-4753 ◽  
Author(s):  
Carla Esposito ◽  
Maxim V. Pethoukov ◽  
Dmitri I. Svergun ◽  
Alessia Ruggiero ◽  
Carlo Pedone ◽  
...  

ABSTRACT Heparin-binding hemagglutinin (HBHA) is a virulence factor of tuberculosis which is responsible for extrapulmonary dissemination of this disease. A thorough biochemical characterization of HBHA has provided experimental evidence of a coiled-coil nature of HBHA. These data, together with the low-resolution structures of a full-length form and a truncated form of HBHA obtained by small-angle X-ray scattering, have unambiguously indicated that HBHA has a dimeric structure with an elongated shape.


2015 ◽  
Vol 108 (2) ◽  
pp. 375a
Author(s):  
Donghyuk Shin ◽  
Seungsu Han ◽  
Gwanho Kim ◽  
Gyu Hee Kim ◽  
Xu Xheng ◽  
...  

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Benjamin G Horst ◽  
Adam L Yokom ◽  
Daniel J Rosenberg ◽  
Kyle L Morris ◽  
Michal Hammel ◽  
...  

Soluble guanylate cyclase (sGC) is the primary receptor for nitric oxide (NO) in mammalian nitric oxide signaling. We determined structures of full-length Manduca sexta sGC in both inactive and active states using cryo-electron microscopy. NO and the sGC-specific stimulator YC-1 induce a 71° rotation of the heme-binding β H-NOX and PAS domains. Repositioning of the β H-NOX domain leads to a straightening of the coiled-coil domains, which, in turn, use the motion to move the catalytic domains into an active conformation. YC-1 binds directly between the β H-NOX domain and the two CC domains. The structural elongation of the particle observed in cryo-EM was corroborated in solution using small angle X-ray scattering (SAXS). These structures delineate the endpoints of the allosteric transition responsible for the major cyclic GMP-dependent physiological effects of NO.


2019 ◽  
Author(s):  
Benjamin G. Horst ◽  
Adam L. Yokom ◽  
Daniel J. Rosenberg ◽  
Kyle L. Morris ◽  
Michal Hammel ◽  
...  

AbstractSoluble guanylate cyclase (sGC) is the primary receptor for nitric oxide (NO) in mammalian nitric oxide signaling. We determined structures of full-lengthManduca sextasGC in both inactive and active states using cryo-electron microscopy. NO and the sGC-specific stimulator YC-1 induce a 71° rotation of the heme-binding β H-NOX and PAS domains. Repositioning of the β H-NOX domain leads to a straightening of the coiled-coil domains, which, in turn, use the motion to move the catalytic domains into an active conformation. YC-1 binds directly between the β H-NOX domain and the two CC domains. The structural elongation of the particle observed in cryo-EM was corroborated in solution using small angle X-ray scattering (SAXS). These structures delineate the endpoints of the allosteric transition responsible for the major cyclic GMP-dependent physiological effects of NO.


1991 ◽  
Vol 88 (2) ◽  
pp. 561-564 ◽  
Author(s):  
R. Rasmussen ◽  
D. Benvegnu ◽  
E. K. O'Shea ◽  
P. S. Kim ◽  
T. Alber

2021 ◽  
Author(s):  
Ariana Peck ◽  
Hsing-Yin Chang ◽  
Antoine Dujardin ◽  
Deeban Ramalingam ◽  
Monarin Uervirojnangkoorn ◽  
...  

X-ray free electron lasers (XFEL) have the ability to produce ultra-bright femtosecond X-ray pulses for coherent diffraction imaging of biomolecules. While the development of methods and algorithms for macromolecular crystallography is now mature, XFEL experiments involving aerosolized or solvated biomolecular samples offer new challenges both in terms of experimental design and data processing. Skopi is a simulation package that can generate single-hit diffraction images for reconstruction algorithms, multi-hit diffraction images of aggregated particles for training machine learning classification tasks using labeled data, diffraction images of randomly distributed particles for fluctuation X-ray scattering (FXS) algorithms, and diffraction images of reference and target particles for holographic reconstruction algorithms. We envision skopi as a resource to aid the development of on-the-fly feedback during non-crystalline experiments at XFEL facilities, which will provide critical insights into biomolecular structure and function.


2014 ◽  
Vol 70 (a1) ◽  
pp. C1599-C1599
Author(s):  
François Ferron ◽  
David Blocquel ◽  
Johnny Habchi ◽  
Eric Durand ◽  
Marion Sevajol ◽  
...  

The structural characterization of various constructs of the Measles virus (MeV) Phosphoprotein (P) multimerization domain (PMD) has brought to light significant discrepancies in the quaternary structure due to both crystal constraints and the flexible nature of this coiled-coil. Indeed, despite a conserved tetrameric parallel coiled-coil core, structural comparison unveiled significant deformations in the C-terminal extremities that even led to the partial unfolding of the coiled-coil. These deformations were induced by intermolecular interactions within the crystal, as well as by the crystallization condition. These deformations also suggest that PMD has the ability to adapt to external mechanical constrains. Using a combination of biophysical methods (size-exclusion chromatography, circular dichroism and small angle X-ray scattering), we assessed the differential flexibility of the C-terminal region of the MeV PMD in solution. Taken together, these results show that crystal packing can be used to "freeze" in a certain state, parts of proteins known to be in a dynamic folding-unfolding equilibrium. They also bring awareness that conclusions about function and mechanism based on analysis of a single crystal structure of a known dynamic protein can be easily biased, and they challenge to some extent the assumption that coiled-coil structures can be reliably predicted from the amino acid sequence.


Biochemistry ◽  
2003 ◽  
Vol 42 (7) ◽  
pp. 2195-2201 ◽  
Author(s):  
Tsuyoshi Yokouchi ◽  
Hideki Nogami ◽  
Yoshinobu Izumi ◽  
Hidenori Yoshino ◽  
Ken-ichi Nakashima ◽  
...  

2013 ◽  
Vol 19 (5) ◽  
pp. 283-292 ◽  
Author(s):  
Leila Malik ◽  
Jesper Nygaard ◽  
Niels J. Christensen ◽  
Werner W. Streicher ◽  
Peter W. Thulstrup ◽  
...  

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