Human full‐length Securin is a natively unfolded protein

Sánchez-Puig, Nuria; Veprintsev, Dmitry B.; Fersht, Alan R.

doi:10.1110/ps.051368005

Cited by 66 publications

(71 citation statements)

References 53 publications

(55 reference statements)

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“…[20][21][22][23][24][25][26] This suggests that many IDPs undergo a structural change with increasing temperature. Different models have been put forward to explain this observation; however, the data do not decisively determine which explanation is correct, mainly because of the lack of atomic resolution information.…”

Section: Discussionmentioning

confidence: 99%

“…Most of these studies have identified structural changes upon heating that were interpreted mostly as formation of a-helices and to a minor extent to a loss of PPII structure. [20][21][22][23][24][25][26] The interpretation of the changes observed by CD spectroscopy is ambiguous. This is caused by the low resolution of this technique and the fact that structural changes in different segments may have spectroscopic contributions that cancel each other's signal.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Temperature‐dependent structural changes in intrinsically disordered proteins: Formation of α‒helices or loss of polyproline II?

Kjærgaard¹,

Nørholm²,

et al. 2010

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Structural characterization of intrinsically disordered proteins (IDPs) is mandatory for deciphering their potential unique physical and biological properties. A large number of circular dichroism (CD) studies have demonstrated that a structural change takes place in IDPs with increasing temperature, which most likely reflects formation of transient a-helices or loss of polyproline II (PPII) content. Using three IDPs, ACTR, NHE1, and Spd1, we show that the temperature-induced structural change is common among IDPs and is accompanied by a contraction of the conformational ensemble. This phenomenon was explored at residue resolution by multidimensional NMR spectroscopy. Intrinsic chemical shift referencing allowed us to identify regions of transiently formed helices and their temperature-dependent changes in helicity. All helical regions were found to lose rather than gain helical structures with increasing temperature, and accordingly these were not responsible for the change in the CD spectra. In contrast, the nonhelical regions exhibited a general temperature-dependent structural change that was independent of long-range interactions. The temperature-dependent CD spectroscopic signature of IDPs that has been amply documented can be rationalized to represent redistribution of the statistical coil involving a general loss of PPII conformations.Keywords: intrinsically disordered protein (IDP); transient secondary structure; temperature dependence; polyproline II; circular dichroism (CD); nuclear magnetic resonance spectroscopy (NMR); sodium-proton (Na1/H1) exchanger 1 (NHE1); S-phase delayed 1 (Spd1); activator for thyroid hormone and retinoid receptors (ACTR) Abbreviations: ACTR, activator for thyroid hormone and retinoid receptors; CBP, CREB-binding protein; CD, circular dichroism; IDP, intrinsically disordered protein; NCBD, nuclear coactivator binding domain; NHE1cdt, sodium-proton (Na þ /H þ ) exchanger 1 C-terminal distal tail; NMR, nuclear magnetic resonance; PPII, polyproline II; RDC, residual dipolar coupling; SAXS, small-angle X-ray scattering; Spd1, S-phase delayed 1.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Temperature‐dependent structural changes in intrinsically disordered proteins: Formation of α‒helices or loss of polyproline II?

Kjærgaard¹,

Nørholm²,

et al. 2010

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“…If such fluctuations opened the substrate binding/catalytic interface, they could aid in product release, which could be the rate limiting step for PP2A as it is for many enzymes (56). This effect might, for example, contribute to PP2A's activity toward multiply phosphorylated proteins, e.g., the unstructured proteins securin (57) or Tau, whose hyperphosphorylation in the absence of PP2A results in microtubule damage and formation of neurofibrillary tangles diagnostic of Alzheimer's disease (58). Further, under normal conditions, Tau remains bound to the enzyme's B subunit during sequential cycles of capture, catalysis, and release, followed by reconfiguration and capture of another phosphate (58).…”

Section: Discussionmentioning

confidence: 99%

PR65, the HEAT-repeat scaffold of phosphatase PP2A, is an elastic connector that links force and catalysis

Grinthal¹,

Adamovic

Weiner³

et al. 2010

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

116

114

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PR65 is the two-layered (α-α solenoid) HEAT-repeat (Huntingtin, elongation factor 3, a subunit of protein phosphatase 2A, PI3 kinase target of rapamycin 1) scaffold of protein phosphatase PP2A. Molecular dynamics simulations predict that, at forces expected in living systems, PR65 undergoes (visco-)elastic deformations in response to pulling/pushing on its ends. At lower forces, smooth global flexural and torsional changes occur via even redistribution of stress along the hydrophobic core of the molecule. At intermediate forces, helix-helix separation along one layer ("fracturing") leads to global relaxation plus loss of contact in the other layer to unstack the affected units. Fracture sites are determined by unusual sequences in contiguous interhelix turns. Normal mode analysis of the heterotrimeric PP2A enzyme reveals that its ambient conformational fluctuations are dominated by elastic deformations of PR65, which introduce a mechanical linkage between the separately bound regulatory and catalytic subunits. PR65-dominated fluctuations of PP2A have the effect of opening and closing the enzyme's substrate binding/catalysis interface, as well as altering the positions of certain catalytic residues. These results suggest that substrate binding/catalysis are sensitive to mechanical force. Force could be imposed from the outside (e.g., in PP2A's response to spindle tension) or arise spontaneously (e.g., in PP2A's interaction with unstructured proteins such as Tau, a microtubule-associated Alzheimer's-implicated protein). The presented example supports the view that conformation and function of protein complexes can be modulated by mechanical energy inputs, as well as by chemical energy inputs from ligand binding. Given that helical-repeat proteins are involved in many cellular processes, the findings also encourage the view that mechanical forces may be of widespread importance.helical-repeat protein | protein elasticity | protein mechanotransduction | spindle tension

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“…Previous findings which utilized undefined sources of binding partners (containing intact spectrin as well as other membrane and non-membrane proteins) could account for the different outcomes in earlier versus the present work. Perhaps for this reason, it is not uncommon that other interactions of proteins originally detected in undefined systems cannot be confirmed in defined systems (59).…”

Section: Affinity and Kinetic Analysis Of Abd To Zu5 By Surface Plasmmentioning

confidence: 99%

Molecular Epitopes of the Ankyrin−Spectrin Interaction

et al. 2008

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Isoforms of ankyrin and its binding partner spectrin are responsible for a number of interactions in a variety of human cells. Conflicting evidence, however, had identified two different, non-overlapping human erythroid ankyrin subdomains, Zu5 and 272, as the minimum binding region for β-spectrin. Complementary studies on the ankyrin-binding domain of spectrin have been somewhat more conclusive yet have not presented binding in terms of well-phased, integral numbers of spectrin repeats. Thus, the objective of this study was to clearly define and characterize the minimal ankyrin−spectrin binding epitopes. Circular dichroism (CD) wavelength spectra of the aforementioned ankyrin subdomains show that these fragments are 30−60% unstructured. In contrast, human erythroid β-spectrin repeats 13, 14, 15, and 16 (prepared in all combinations of two adjacent repeats) demonstrated proper folding and stability as determined by CD and tryptophan wavelength and heat denaturation scans. Native polyacrylamide gel electrophoresis (PAGE) gel shifts as well as affinity pull-down assays implicated Zu5 and β-spectrin repeats 14−15 as the minimum binding epitopes. These results were confirmed by analytical ultracentrifugation to sedimentation equilibrium by which a 1:1 complex was obtained if and only if Zu5 was mixed with β-spectrin constructs containing repeats 14 and 15 in tandem. Surface plasmon resonance yielded a K D of 15.2 nM for binding of β-spectrin fragments to the ankyrin subdomain Zu5, accounting for all of the binding observed between the intact molecules. Collectively, these results show the 14th and 15th β-spectrin repeats comprise the minimal, phased region of β-spectrin, which binds ankyrin at the Zu5 subdomain with high affinity.

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Human full‐length Securin is a natively unfolded protein

Cited by 66 publications

References 53 publications

Temperature‐dependent structural changes in intrinsically disordered proteins: Formation of α‒helices or loss of polyproline II?

Temperature‐dependent structural changes in intrinsically disordered proteins: Formation of α‒helices or loss of polyproline II?

PR65, the HEAT-repeat scaffold of phosphatase PP2A, is an elastic connector that links force and catalysis

Molecular Epitopes of the Ankyrin−Spectrin Interaction

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