A Slow Conformational Switch in the BMAL1 Transactivation Domain Modulates Circadian Rhythms

Gustafson, Chelsea L; Parsley, Nicole C.; Asimgil, Hande; Lee, Hsiau‐Wei; Ahlbach, Christopher; Michael, Alicia K.; Xu, Hongwei; Williams, Owen L.; Davis, T.; Liu, Andrew C.; Partch, Carrie L.

doi:10.1016/j.molcel.2017.04.011

Cited by 73 publications

(82 citation statements)

References 76 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We, therefore, believe that it is likely the prolines within the first 30 residues of PRPF4 that represent part of the weak-affinity-binding site for PPIH. This is the first direct interaction found between a spliceosomal protein and the active site of a spliceosomal cyclophilin, although we note that there are multiple examples of isomerase-dependent interactions with other nuclear proteins [45–49]. PRPF4 1–98 is specific for PPIH over PPIA, indicating that there are interactions outside the isomerase active site that are important for this interaction (Figure 8).…”

Section: Discussionmentioning

confidence: 84%

The spliceosomal proteins PPIH and PRPF4 exhibit bi-partite binding

Rajiv

Jackson

Simon

et al. 2017

Biochemical Journal

Self Cite

View full text Add to dashboard Cite

Pre-mRNA splicing is a dynamic, multistep process that is catalyzed by the RNA (ribonucleic acid)–protein complex called the spliceosome. The spliceosome contains a core set of RNAs and proteins that are conserved in all organisms that perform splicing. In higher organisms, peptidyl-prolyl isomerase H (PPIH) directly interacts with the core protein pre-mRNA processing factor 4 (PRPF4) and both integrate into the pre-catalytic spliceosome as part of the tri-snRNP (small nuclear RNA–protein complex) subcomplex. As a first step to understand the protein interactions that dictate PPIH and PRPF4 function, we expressed and purified soluble forms of each protein and formed a complex between them. We found two sites of interaction between PPIH and the N-terminus of PRPF4, an unexpected result. The N-terminus of PRPF4 is an intrinsically disordered region and does not adopt secondary structure in the presence of PPIH. In the absence of an atomic resolution structure, we used mutational analysis to identify point mutations that uncouple these two binding sites and find that mutations in both sites are necessary to break up the complex. A discussion of how this bipartite interaction between PPIH and PRPF4 may modulate spliceosomal function is included.

show abstract

Section: Discussionmentioning

confidence: 84%

The spliceosomal proteins PPIH and PRPF4 exhibit bi-partite binding

Rajiv

Jackson

Simon

et al. 2017

Biochemical Journal

Self Cite

View full text Add to dashboard Cite

show abstract

“…The tunable stabilization of cis conformers by π·CH interaction between the aromatic sidechain and the proline ring has been described mainly for small molecules and peptides [55,56,71] and recently for the TAD domain of BMAL1 [72]. This stabilization is limited to prolines (at position i) and aromatics in positions i±1 and i-2.…”

Section: Discussionmentioning

confidence: 99%

The Ambivalent Role of Proline Residues in an Intrinsically Disordered Protein: From Disorder Promoters to Compaction Facilitators

Mateos

Conrad-Billroth

Schiavina

et al. 2020

Journal of Molecular Biology

View full text Add to dashboard Cite

Intrinsically disordered proteins (IDPs) carry out many biological functions. They lack a stable three-dimensional structure, but rather adopt many different conformations in dynamic equilibrium. The interplay between local dynamics and global rearrangements is key for their function. In IDPs, proline residues are significantly enriched. Given their unique physicochemical and structural properties, a more detailed understanding of their potential role in stabilizing partially folded states in IDPs is highly desirable. Nuclear magnetic resonance (NMR) spectroscopy, and in particular 13 C-detected NMR, is especially suitable to address these questions. We applied a 13 C-detected strategy to study Osteopontin, a largely disordered IDP with a central compact region. By employing the exquisite sensitivity and spectral resolution of these novel techniques we gained unprecedented insight into cis-Pro populations, their local structural dynamics and their role in mediating long-range contacts. Our findings clearly call for a reassessment of the structural and functional role of proline residues in IDPs. The emerging picture shows that proline residues have ambivalent structural roles. They are not simply disorder promoters but rather can, depending on the primary sequence context, act as nucleation sites for structural compaction in IDPs. These unexpected features provide a versatile mechanistic toolbox to enrich the conformational ensembles of IDPs with specific features for adapting to changing molecular and cellular environments.

show abstract

“…2) challenges the idea that the BMAL1 TAD is key to circadian repression (13,14,30) and shows that, at least in the butterfly, the BMAL1 TAD α-helix is not required for circadian repression by vertebrate-like CRY. The delayed phase of adult eclosion (by ∼1 h on DD day 1) observed in butterfly mutants lacking the TAD α-helix is nevertheless consistent with the TAD α-helix having a role in phase or period determination, similar to its function in mammals (13,14).…”

Section: Discussionmentioning

confidence: 99%

Vertebrate-like CRYPTOCHROME 2 from monarch regulates circadian transcription via independent repression of CLOCK and BMAL1 activity

Zhang

Markert

Groves

et al. 2017

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

View full text Add to dashboard Cite

Circadian repression of CLOCK-BMAL1 by PERIOD and CRYPTOCHROME (CRY) in mammals lies at the core of the circadian timekeeping mechanism. CRY repression of CLOCK-BMAL1 and regulation of circadian period are proposed to rely primarily on competition for binding with coactivators on an α-helix located within the transactivation domain (TAD) of the BMAL1 C terminus. This model has, however, not been tested in vivo. Here, we applied CRISPR/Cas9-mediated mutagenesis in the monarch butterfly (Danaus plexippus), which possesses a vertebrate-like CRY (dpCRY2) and an ortholog of BMAL1, to show that insect CRY2 regulates circadian repression through TAD α-helix-dependent and -independent mechanisms. Monarch mutants lacking the BMAL1 C terminus including the TAD exhibited arrhythmic eclosion behavior. In contrast, mutants lacking the TAD α-helix but retaining the most distal C-terminal residues exhibited robust rhythms during the first day of constant darkness (DD1), albeit with a delayed peak of eclosion. Phase delay in this mutant on DD1 was exacerbated in the presence of a single functional allele of dpCry2, and rhythmicity was abolished in the absence of dpCRY2. Reporter assays in Drosophila S2 cells further revealed that dpCRY2 represses through two distinct mechanisms: a TADdependent mechanism that involves the dpBMAL1 TAD α-helix and dpCLK W328 and a TAD-independent mechanism involving dpCLK E333. Together, our results provide evidence for independent mechanisms of vertebrate-like CRY circadian regulation on the BMAL1 C terminus and the CLK PAS-B domain and demonstrate the importance of a BMAL1 TAD-independent mechanism for generating circadian rhythms in vivo.circadian clock | CRYPTOCHROME 2 | BMAL1 C terminus | CLOCK | CRISPR

show abstract

A Slow Conformational Switch in the BMAL1 Transactivation Domain Modulates Circadian Rhythms

Cited by 73 publications

References 76 publications

The spliceosomal proteins PPIH and PRPF4 exhibit bi-partite binding

The spliceosomal proteins PPIH and PRPF4 exhibit bi-partite binding

The Ambivalent Role of Proline Residues in an Intrinsically Disordered Protein: From Disorder Promoters to Compaction Facilitators

Vertebrate-like CRYPTOCHROME 2 from monarch regulates circadian transcription via independent repression of CLOCK and BMAL1 activity

Contact Info

Product

Resources

About