Cryo-EM structures of SERCA2b reveal the mechanism of regulation by the luminal extension tail

Zhang, Yuxia; Inoue, Masayasu; Tsutsumi, Akihisa; Watanabe, Satoshi; Nishizawa, Takashi; Nagata, Kazuhiro; Kikkawa, Masahide; Inaba, Kenji

doi:10.1101/2020.03.28.012849

Cited by 10 publications

(42 citation statements)

References 27 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We expressed and purified SERCA2b essentially as described previously (Inoue et al, 2019;Zhang et al, 2020 . However, the resolution of the "possible-open-form" cryo-EM map was low (˜12 A resolution), and not improved by additional 3D classifications, probably due to the highly mobile cytosolic domains or the ensemble of their heterogeneous arrangements in this state.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca ²⁺ ‐ATPase SERCA2b

et al. 2021

Self Cite

View full text Add to dashboard Cite

Sarco/endoplasmic reticulum Ca 2+ -ATPase (SERCA) 2b is a ubiquitous SERCA family member that conducts Ca 2+ uptake from the cytosol to the ER. Herein, we present a 3.3 A resolution cryoelectron microscopy (cryo-EM) structure of human SERCA2b in the E1Á2Ca 2+ state, revealing a new conformation for Ca 2+ -bound SERCA2b with a much closer arrangement of cytosolic domains than in the previously reported crystal structure of Ca 2+ -bound SERCA1a. Multiple conformations generated by 3D classification of cryo-EM maps reflect the intrinsically dynamic nature of the cytosolic domains in this state. Notably, ATP binding residues of SERCA2b in the E1Á2Ca 2+ state are located at similar positions to those in the E1Á2Ca 2+ -ATP state; hence, the cryo-EM structure likely represents a preformed state immediately prior to ATP binding. Consistently, a SERCA2b mutant with an interdomain disulfide bridge that locks the closed cytosolic domain arrangement displayed significant autophosphorylation activity in the presence of Ca 2+ . We propose a novel mechanism of ATP binding to SERCA2b.

show abstract

Section: Resultsmentioning

confidence: 99%

“…Eventually, these domains were settled at the intermediate positions between those in the present "closed-form" cryo-EM structure of SERCA2b and those in the "open-form" crystal structure of SERCA1a. (Zhang et al, 2020).…”

Section: Resultsmentioning

confidence: 99%

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca ²⁺ ‐ATPase SERCA2b

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

“…The loop L6-7 has moreover been suggested to be part of an ion access pathway in both SERCA and the Na + /K + -ATPase (12,13,15,16,28), and/or to contribute to the coordination of events between the cytosolic and transmembrane domains (14,16,17). A very recent study on SER-CA2b has found that small, local conformational changes in the area around the L6-7-P1 interaction-in this case induced by long-range effects from changes to the luminal region of the M domain-are accompanied by changes to the entire headpiece arrangement (29). In light of our finding that the E340A mutation allows for an irreversible swinging out of Arg822, which is correlated to a concomitant inward movement of M3, the reverse conclusion must be that the interaction network between Arg822, Glu340, and Leu249 is critical for maintaining a proper architecture of the Ca 2+ entry and exit pathways.…”

Section: Discussionmentioning

confidence: 99%

The SERCA residue Glu340 mediates interdomain communication that guides Ca ²⁺ transport

Geurts

Clausen

Arnou

et al. 2020

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

The sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) is a P-type ATPase that transports Ca2+ from the cytosol into the sarco(endo)plasmic reticulum (SR/ER) lumen, driven by ATP. This primary transport activity depends on tight coupling between movements of the transmembrane helices forming the two Ca2+-binding sites and the cytosolic headpiece mediating ATP hydrolysis. We have addressed the molecular basis for this intramolecular communication by analyzing the structure and functional properties of the SERCA mutant E340A. The mutated Glu340 residue is strictly conserved among the P-type ATPase family of membrane transporters and is located at a seemingly strategic position at the interface between the phosphorylation domain and the cytosolic ends of 5 of SERCA’s 10 transmembrane helices. The mutant displays a marked slowing of the Ca2+-binding kinetics, and its crystal structure in the presence of Ca2+ and ATP analog reveals a rotated headpiece, altered connectivity between the cytosolic domains, and an altered hydrogen bonding pattern around residue 340. Supported by molecular dynamics simulations, we conclude that the E340A mutation causes a stabilization of the Ca2+ sites in a more occluded state, hence displaying slowed dynamics. This finding underpins a crucial role of Glu340 in interdomain communication between the headpiece and the Ca2+-binding transmembrane region.

show abstract

“…Interestingly, the impact of ERp57 on Ca 2+ oscillations was observed for SERCA2b but not SERCA2a, and it was postulated that the isoform specificity may relate to the divergent C terminus in SERCA2b [ 141 ]. It will be exciting if one can confirm an isoform specific regulation via the lumenal cysteines that connects to the unique structural conformations influenced by the C terminus [ 145 , 146 ]. However, not all studies suggest isoform specific oxidation/reduction of SERCA2; SEPN1 was shown to associate with both SERCA2a and SERCA2b [ 136 ].…”

Section: Er Targets Of H 2 Omentioning

confidence: 99%

Pathways for Sensing and Responding to Hydrogen Peroxide at the Endoplasmic Reticulum

Roscoe

Sevier

2020

Cells

View full text Add to dashboard Cite

The endoplasmic reticulum (ER) has emerged as a source of hydrogen peroxide (H2O2) and a hub for peroxide-based signaling events. Here we outline cellular sources of ER-localized peroxide, including sources within and near the ER. Focusing on three ER-localized proteins—the molecular chaperone BiP, the transmembrane stress-sensor IRE1, and the calcium pump SERCA2—we discuss how post-translational modification of protein cysteines by H2O2 can alter ER activities. We review how changed activities for these three proteins upon oxidation can modulate signaling events, and also how cysteine oxidation can serve to limit the cellular damage that is most often associated with elevated peroxide levels.

show abstract

Cryo-EM structures of SERCA2b reveal the mechanism of regulation by the luminal extension tail

Cited by 10 publications

References 27 publications

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca ²⁺ ‐ATPase SERCA2b

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca ²⁺ ‐ATPase SERCA2b

The SERCA residue Glu340 mediates interdomain communication that guides Ca ²⁺ transport

Pathways for Sensing and Responding to Hydrogen Peroxide at the Endoplasmic Reticulum

Contact Info

Product

Resources

About

Cryo-EM structures of SERCA2b reveal the mechanism of regulation by the luminal extension tail

Cited by 10 publications

References 27 publications

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca 2+ ‐ATPase SERCA2b

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca 2+ ‐ATPase SERCA2b

The SERCA residue Glu340 mediates interdomain communication that guides Ca 2+ transport

Pathways for Sensing and Responding to Hydrogen Peroxide at the Endoplasmic Reticulum

Contact Info

Product

Resources

About

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca ²⁺ ‐ATPase SERCA2b

Cryo‐EM analysis provides new mechanistic insight into ATP binding to Ca ²⁺ ‐ATPase SERCA2b

The SERCA residue Glu340 mediates interdomain communication that guides Ca ²⁺ transport