Critical Role of Glu40-Ser48 Loop Linking Actuator Domain and First Transmembrane Helix of Ca2+-ATPase in Ca2+ Deocclusion and Release from ADP-insensitive Phosphoenzyme

Daiho, Takashi; Yamasaki, Kazuo; Dankó, Stefánia; Suzuki, Hiroshi

doi:10.1074/jbc.m707665200

Cited by 57 publications

(94 citation statements)

References 60 publications

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“…E1PCa 2 to E2P transition. The result agrees with the established mechanism that the two Ca 2ϩ ions are occluded in E1PCa 2 , and Ca 2ϩ release into the lumen occurs very rapidly after the rate-limiting E1PCa 2 to E2PCa 2 transition, E1PCa 2 3 E2PCa 2 3 E2P ϩ 2Ca 2ϩ (11)(12)(13)(14). Thus, the EP transition and Ca 2ϩ release are tightly coupled in the presence of K ϩ .…”

Section: Time Courses Of Ep Decay and Casupporting

confidence: 79%

“…Ca 2ϩ deocclusion and release (steps [3][4]. Ca 2ϩ release in step 4 is very rapid, so that an E2PCa 2 intermediate state does not accumulate and in fact had never been found until we recently established its existence (10 -13) and successfully trapped it for the first time (14). Finally, E2P is hydrolyzed back to the inactive E2 form (step 5).…”

Section: During Camentioning

confidence: 99%

“…The A/M1Ј-linker of correct length has a critical function in inclining and compacting the E2P structure (14,27). The structure is stabilized by three critical interaction networks; at the Tyr 122 HC (hydrophobic interaction cluster involving the A and P domains and M2), at the Val 200 loop (ionic and hydrogen bonding interactions with the P domain residues), and at the TGES 184 loop (hydrogen bonding interactions with the P domain residue in the catalytic site) (10 -14).…”

Section: Ca 2ϩ Release From E1pca 2 In Absence Of Kmentioning

confidence: 99%

“…The TGES 184 loop of the rotated A domain protrudes into the catalytic site and blocks attack of ADP on the Asp 351 phosphate (causing the loss of ADP sensitivity). The Tyr 122 HC is produced upon A-P domain inclination induced by tension on the A/M1Ј-linker (14,27) and is critical for reducing the Ca 2ϩ affinity and opening the lumenal gate, i.e. to deocclude/release Ca 2ϩ , E2PCa 2 3 E2P (11-13).…”

Section: Ca 2ϩ Release From E1pca 2 In Absence Of Kmentioning

confidence: 99%

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Ca2+ Release to Lumen from ADP-sensitive Phosphoenzyme E1PCa2 without Bound K+ of Sarcoplasmic Reticulum Ca2+-ATPase

Yamasaki

Daiho

Dankó

et al. 2010

Journal of Biological Chemistry

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Section: Time Courses Of Ep Decay and Casupporting

confidence: 79%

Section: During Camentioning

confidence: 99%

Section: Ca 2ϩ Release From E1pca 2 In Absence Of Kmentioning

confidence: 99%

Section: Ca 2ϩ Release From E1pca 2 In Absence Of Kmentioning

confidence: 99%

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Ca2+ Release to Lumen from ADP-sensitive Phosphoenzyme E1PCa2 without Bound K+ of Sarcoplasmic Reticulum Ca2+-ATPase

Yamasaki

Daiho

Dankó

et al. 2010

Journal of Biological Chemistry

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“…Thus in E2P, these domains produce the most compactly organized state (see Fig. 2 (27,28). The importance of the interdomain interaction between Arg 678 (P) and Asp 203 (A) in stabilizing the E2P and E2 intermediates and its influence on modulatory ATP activation were pointed out by the mutation R678A (29).…”

Section: Sarcoplasmic Reticulum Camentioning

confidence: 99%

Roles of Interaction between Actuator and Nucleotide Binding Domains of Sarco(endo)plasmic Reticulum Ca2+-ATPase as Revealed by Single and Swap Mutational Analyses of Serine 186 and Glutamate 439

Liu

Daiho

Yamasaki

et al. 2009

Journal of Biological Chemistry

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Roles of hydrogen bonding interaction between Ser 186 of the actuator (A) domain and Glu 439 of nucleotide binding (N) domain seen in the structures of ADP-insensitive phosphorylated intermediate (E2P) of sarco(endo)plasmic reticulum Ca2؉ -ATPase were explored by their double alanine substitution S186A/E439A, swap substitution S186E/E439S, and each of these single substitutions. All the mutants except the swap mutant S186E/E439S showed markedly reduced Ca 2؉ -ATPase activity, and S186E/E439S restored completely the wild-type activity. In all the mutants except S186E/E439S, the isomerization of ADP-sensitive phosphorylated intermediate (E1P) to E2P was markedly retarded, and the E2P hydrolysis was largely accelerated, whereas S186E/E439S restored almost the wildtype rates. Results showed that the Ser 186 -Glu 439 hydrogen bond stabilizes the E2P ground state structure. The modulatory ATP binding at sub-mMϳmM range largely accelerated the EP isomerization in all the alanine mutants and E439S. In S186E, this acceleration as well as the acceleration of the ATPase activity was almost completely abolished, whereas the swap mutation S186E/E439S restored the modulatory ATP acceleration with a much higher ATP affinity than the wild type. Results indicated that Ser 186 and Glu 439 are closely located to the modulatory ATP binding site for the EP isomerization, and that their hydrogen bond fixes their side chain configurations thereby adjusts properly the modulatory ATP affinity to respond to the cellular ATP level.Sarcoplasmic reticulum Ca 2ϩ -ATPase (SERCA1a) 2 is a representative member of P-type ion-transporting ATPases and catalyzes Ca 2ϩ transport coupled with ATP hydrolysis (Fig. 1) (1-9). In the catalytic cycle, the enzyme is activated by binding of two Ca 2ϩ ions at the transport sites (E2 to E1Ca 2 , steps 1-2) and then autophosphorylated at Asp 351 with MgATP to form ADP-sensitive phosphoenzyme (E1P, step 3), which can react with ADP to regenerate ATP. Upon formation of this EP, the bound Ca 2ϩ ions are occluded in the transport sites (E1PCa 2 ). The subsequent isomeric transition to ADP-insensitive form (E2P) results in a change in the orientation of the Ca 2ϩ binding sites and reduction of their affinity, and thus Ca 2ϩ release into lumen (steps 4 and 5). Finally, the hydrolysis takes place and returns the enzyme into an unphosphorylated and Ca 2ϩ -unbound form (E2, step 6). E2P can also be formed from P i in the presence of Mg 2ϩ and the absence of Ca 2ϩ by reversal of its hydrolysis.The cytoplasmic three domains N, A, and P largely move and change their organization states during the Ca 2ϩ transport cycle (10 -22). These changes are linked with the rearrangements in the transmembrane helices. In the EP isomerization (loss of ADP sensitivity) and Ca 2ϩ release, the A domain largely rotates (by ϳ110°parallel to membrane plane), intrudes into the space between the N and P domains, and the P domain largely inclines toward the A domain. Thus in E2P, these domains produce the most compactly organized state (see Fi...

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White and gray matter abnormalities in the brain of patients with fibromyalgia: A diffusion‐tensor and volumetric imaging study

Lutz¹,

Jäger²,

Quervain³

et al. 2008

Arthritis & Rheumatism

239

181

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Objective. To use a combination of magnetic resonance diffusion-tensor imaging (MR-DTI) and MR imaging of voxel-based morphometry (MR-VBMFibromyalgia syndrome (FMS) belongs to a group of common functional somatic syndromes that are characterized by chronic widespread pain and are often accompanied by functional disturbance (dizziness, vertigo, palpitations, and peripheral edema) in different organ systems and symptoms of sleep disturbance, anxiety, memory problems, fatigue, and exhaustion. Because of the association between FMS development and severe organic illness, accidents, or stressful life events, FMS has also been regarded as a stress-related disorder (1). The combination of chronic widespread pain, sleep disturbance, and pronounced and ongoing stress symptoms is highly disabling, yet there is no universally effective treatment, and the pathophysiologic features of FMS are incompletely understood. Although this disorder has frequently been described as musculoskeletal or Supported by funds from the Departments of Anaesthesiology and Radiology, Klinikum Grosshadern, Ludwig-Maximilians University.

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Critical Role of Glu40-Ser48 Loop Linking Actuator Domain and First Transmembrane Helix of Ca2+-ATPase in Ca2+ Deocclusion and Release from ADP-insensitive Phosphoenzyme

Cited by 57 publications

References 60 publications

Ca2+ Release to Lumen from ADP-sensitive Phosphoenzyme E1PCa2 without Bound K+ of Sarcoplasmic Reticulum Ca2+-ATPase

Ca2+ Release to Lumen from ADP-sensitive Phosphoenzyme E1PCa2 without Bound K+ of Sarcoplasmic Reticulum Ca2+-ATPase

Roles of Interaction between Actuator and Nucleotide Binding Domains of Sarco(endo)plasmic Reticulum Ca2+-ATPase as Revealed by Single and Swap Mutational Analyses of Serine 186 and Glutamate 439

White and gray matter abnormalities in the brain of patients with fibromyalgia: A diffusion‐tensor and volumetric imaging study

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