Stepwise Solid‐Phase Synthesis and Spontaneous Homodimerization of the Helix‐Loop‐Helix Protein Id3

Svobodová, J; Cabrele, Chiara

doi:10.1002/cbic.200600059

Cited by 8 publications

(8 citation statements)

References 39 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The HLH and flanking regions display different structural properties: indeed, the Id HLH domain undergoes self- (Id2 [ 52 ], Id3 [ 53 , 54 ]) or heteroassociation with the HLH domains of class I and II proteins and folds into a four-helix bundle, as shown by the crystal structure of the Id2 HLH domain (PDB ID: 4AYA) [ 55 ] and by the solution NMR structure of the Id3 HLH domain (PDB ID: 2LFH) [ 56 ] (Fig. 2d ).…”

Section: Structural Featuresmentioning

confidence: 99%

“…In contrast, the N-terminal and C-terminal domains are mainly disordered, as suggested by disorder probability prediction analysis [ 57 – 59 ] as well as by conformational data on synthetic peptides reproducing the N-terminal and C-terminal regions of the Id proteins [ 42 , 43 ]. Therefore, the Id proteins contain intrinsically disordered regions that, in the case of the HLH region, undergo folding upon self- or heteroassociation [ 41 , 44 , 53 , 55 , 56 ]. A common feature of intrinsically disordered proteins is the high propensity to aggregate and precipitate, which represents the major obstacle for the structural investigation of these proteins.…”

Section: Structural Featuresmentioning

confidence: 99%

See 1 more Smart Citation

The Id-protein family in developmental and cancer-associated pathways

2017

Self Cite

View full text Add to dashboard Cite

Inhibitors of DNA binding and cell differentiation (Id) proteins are members of the large family of the helix-loop-helix (HLH) transcription factors, but they lack any DNA-binding motif. During development, the Id proteins play a key role in the regulation of cell-cycle progression and cell differentiation by modulating different cell-cycle regulators both by direct and indirect mechanisms. Several Id-protein interacting partners have been identified thus far, which belong to structurally and functionally unrelated families, including, among others, the class I and II bHLH transcription factors, the retinoblastoma protein and related pocket proteins, the paired-box transcription factors, and the S5a subunit of the 26 S proteasome. Although the HLH domain of the Id proteins is involved in most of their protein-protein interaction events, additional motifs located in their N-terminal and C-terminal regions are required for the recognition of diverse protein partners. The ability of the Id proteins to interact with structurally different proteins is likely to arise from their conformational flexibility: indeed, these proteins contain intrinsically disordered regions that, in the case of the HLH region, undergo folding upon self- or heteroassociation. Besides their crucial role for cell-fate determination and cell-cycle progression during development, other important cellular events have been related to the Id-protein expression in a number of pathologies. Dysregulated Id-protein expression has been associated with tumor growth, vascularization, invasiveness, metastasis, chemoresistance and stemness, as well as with various developmental defects and diseases. Herein we provide an overview on the structural properties, mode of action, biological function and therapeutic potential of these regulatory proteins.

show abstract

Section: Structural Featuresmentioning

confidence: 99%

Section: Structural Featuresmentioning

confidence: 99%

The Id-protein family in developmental and cancer-associated pathways

2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…However, whereas a significant amount of biological data on the Id proteins has been published, structural and conformational data on these proteins are still limited. In particular, to the best of our knowledge, only the Id3 protein has been investigated so far as intact protein by circular dichroism (CD) spectroscopy [ 17 ]. For the other Id proteins, structural investigation has been carried out on the separated domains: for example, CD studies of synthetic peptides reproducing the HLH, N-terminal and C-terminal regions of the four Id proteins have been reported [ 18 , 19 , 20 , 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

The Recombinant Inhibitor of DNA Binding Id2 Forms Multimeric Structures via the Helix-Loop-Helix Domain and the Nuclear Export Signal

Roschger

Schubert

Regl

et al. 2018

IJMS

Self Cite

View full text Add to dashboard Cite

The inhibitor of DNA binding and cell differentiation 2 (Id2) is a helix-loop-helix (HLH) protein that acts as negative dominant regulator of basic-HLH transcription factors during development and in cancer. The structural properties of Id2 have been investigated so far by using synthetic or recombinant fragments reproducing single domains (N-terminus, HLH, C-terminus): the HLH domain tends to dimerize into a four-helix bundle, whereas the flanking regions are flexible. In this work, the intact protein was expressed in E. coli, solubilized from inclusion bodies with urea, purified and dissolved in water at pH~4. Under these conditions, Id2 was obtained with both cysteine residues disulfide-bonded to β-mercaptoethanol that was present during the solubilization process. Moreover, it existed in a self-assembled state, in which the N-terminus remained highly flexible, while the HLH domain and, surprisingly, part of the C-terminus, which corresponds to the nuclear export signal (NES), both were involved in slowly tumbling, rigid structures. The protein oligomers also formed twisted fibrils that were several micrometers long and up to 80 nm thick. These results show that self-assembly decreases the backbone flexibility of those two protein regions (HLH and NES) that are important for interaction with basic-HLH transcription factors or for nucleocytoplasmic shuttling.

show abstract

“…[13] The three-dimensional structures of the homodimericf orms of the HLH domainso f Id2 and Id3 (PDB ID:4 AYAf or Id2 30-82, [14] and PDB ID:2 LFH for Id3 29-83) [15] are both characterized by the presence of a parallel four-helix bundle. In contrast, the monomeric states of the Id proteins are predicted to contain high degree of flexibility, [16] which seemst ob eacommon feature of eukaryotic transcriptionf actors: [17] in particular,t he HLH domain may undergo folding upon dimerization and oligomerization, [18][19][20] whereas the flanking regions remain flexible. [19][20][21] However,t his does not exclude the latter regions from containing motifs for mo-lecular recognition: for example, in the case of the Id2 protein it has been shown that the C-terminusc ontainsanuclear export signal (NES) and ad estruction box (D-box)t hat are recognized by the nuclear export receptor chromosomer egion maintenance protein 1 [22] and the anaphase-promoting complex, respectively.…”

Section: Introductionmentioning

confidence: 99%

“…In contrast, the monomeric states of the Id proteins are predicted to contain high degree of flexibility, [16] which seemst ob eacommon feature of eukaryotic transcriptionf actors: [17] in particular,t he HLH domain may undergo folding upon dimerization and oligomerization, [18][19][20] whereas the flanking regions remain flexible. [19][20][21] However,t his does not exclude the latter regions from containing motifs for mo-lecular recognition: for example, in the case of the Id2 protein it has been shown that the C-terminusc ontainsanuclear export signal (NES) and ad estruction box (D-box)t hat are recognized by the nuclear export receptor chromosomer egion maintenance protein 1 [22] and the anaphase-promoting complex, respectively. [23] In addition, as hort N-terminal motif of Id2 has been shown to bind the von-Hippel-Lindau ubiquitin ligase complex, whichinhibits ubiquitination of hypoxia inducible factor alpha (HIFa)a nd thus supports the maintenanceo f cancer stem cells.…”

Section: Introductionmentioning

confidence: 99%

Targeting of a Helix‐Loop‐Helix Transcriptional Regulator by a Short Helical Peptide

et al. 2017

Self Cite

View full text Add to dashboard Cite

The Id proteins (Id1-4) are cell-cycle regulators that play a key role during development, in cancer and vascular disorders. They contain a conserved helix-loop-helix (HLH) domain that folds into a parallel four-helix bundle upon self- or hetero-association with basic-HLH transcription factors. By using such protein-protein interactions, the Id proteins inhibit cell differentiation and promote cell-cycle progression. Accordingly, their supporting role in cancer has been convincingly demonstrated, which makes these proteins interesting therapeutic targets. Herein we present a short peptide containing an (i,i+4)-lactam bridge and a hydrophobic (Φ) three-residue motif Φ(i)-Φ(i+3)-Φ(i+6), which adopts a helical conformation in water, shows Id protein binding in the low-micromolar range, penetrates into breast (MCF-7 and T47D) and bladder (T24) cancer cells, accumulates in the nucleus, and decreases cell viability to ∼50 %. Thus, this cyclopeptide is a promising scaffold for the development of Id protein binders that impair cancer cell viability.

show abstract

Stepwise Solid‐Phase Synthesis and Spontaneous Homodimerization of the Helix‐Loop‐Helix Protein Id3

Cited by 8 publications

References 39 publications

The Id-protein family in developmental and cancer-associated pathways

The Id-protein family in developmental and cancer-associated pathways

The Recombinant Inhibitor of DNA Binding Id2 Forms Multimeric Structures via the Helix-Loop-Helix Domain and the Nuclear Export Signal

Targeting of a Helix‐Loop‐Helix Transcriptional Regulator by a Short Helical Peptide

Contact Info

Product

Resources

About