Four-component protein nanocages designed by programmed symmetry breaking.

Four, eight or twenty C3 symmetric protein trimers can be arranged with tetrahedral, octahedral or icosahedral point group symmetry to generate closed cage-like structures. Viruses access more complex higher triangulation number icosahedral architectures by breaking perfect point group symmetry, but nature appears not to have explored similar symmetry breaking for tetrahedral or octahedral symmetries. Here we describe a general design strategy for building higher triangulation number architectures starting from regular polyhedra through pseudosymmetrization of trimeric building blocks.

Design of pseudosymmetric protein hetero-oligomers.

Pseudosymmetric hetero-oligomers with three or more unique subunits with overall structural (but not sequence) symmetry play key roles in biology, and systematic approaches for generating such proteins de novo would provide new routes to controlling cell signaling and designing complex protein materials. However, the de novo design of protein hetero-oligomers with three or more distinct chains with nearly identical structures is a challenging unsolved problem because it requires the accurate design of multiple protein-protein interfaces simultaneously. Here, we describe a divide-and-conquer approach that breaks the multiple-interface design challenge into a set of more tractable symmetric single-interface redesign tasks, followed by structural recombination of the validated homo-oligomers into pseudosymmetric hetero-oligomers.

Sequence-specific targeting of intrinsically disordered protein regions.

A general approach to design proteins that bind tightly and specifically to intrinsically disordered regions (IDRs) of proteins and flexible peptides would have wide application in biological research, therapeutics, and diagnosis. However, the lack of defined structures and the high variability in sequence and conformational preferences has complicated such efforts. We sought to develop a method combining biophysical principles with deep learning to readily generate binders for any disordered sequence.

De novo design of proteins housing excitonically coupled chlorophyll special pairs.

Natural photosystems couple light harvesting to charge separation using a 'special pair' of chlorophyll molecules that accepts excitation energy from the antenna and initiates an electron-transfer cascade. To investigate the photophysics of special pairs independently of the complexities of native photosynthetic proteins, and as a first step toward creating synthetic photosystems for new energy conversion technologies, we designed C-symmetric proteins that hold two chlorophyll molecules in closely juxtaposed arrangements. X-ray crystallography confirmed that one designed protein binds two chlorophylls in the same orientation as native special pairs, whereas a second designed protein positions them in a previously unseen geometry.

design of energy transfer proteins housing excitonically coupled chlorophyll special pairs.

Natural photosystems couple light harvesting to charge separation using a "special pair" of chlorophyll molecules that accepts excitation energy from the antenna and initiates an electron-transfer cascade. To investigate the photophysics of special pairs independent of complexities of native photosynthetic proteins, and as a first step towards synthetic photosystems for new energy conversion technologies, we designed C-symmetric proteins that precisely position chlorophyll dimers. X-ray crystallography shows that one designed protein binds two chlorophylls in a binding orientation matching native special pairs, while a second positions them in a previously unseen geometry.

Stepwise design of pseudosymmetric protein hetero-oligomers.

Pseudosymmetric hetero-oligomers with three or more unique subunits with overall structural (but not sequence) symmetry play key roles in biology, and systematic approaches for generating such proteins would provide new routes to controlling cell signaling and designing complex protein materials. However, the design of protein hetero-oligomers with three or more distinct chains with nearly identical structures is a challenging problem because it requires the accurate design of multiple protein-protein interfaces simultaneously. Here, we describe a divide-and-conquer approach that breaks the multiple-interface design challenge into a set of more tractable symmetric single-interface redesign problems, followed by structural recombination of the validated homo-oligomers into pseudosymmetric hetero-oligomers.

Structures, activity and mechanism of the Type IIS restriction endonuclease PaqCI.

Type IIS restriction endonucleases contain separate DNA recognition and catalytic domains and cleave their substrates at well-defined distances outside their target sequences. They are employed in biotechnology for a variety of purposes, including the creation of gene-targeting zinc finger and TAL effector nucleases and DNA synthesis applications such as Golden Gate assembly. The most thoroughly studied Type IIS enzyme, FokI, has been shown to require multimerization and engagement with multiple DNA targets for optimal cleavage activity; however, details of how it or similar enzymes forms a DNA-bound reaction complex have not been described at atomic resolution.

De novo design of protein homodimers containing tunable symmetric protein pockets.

Function follows form in biology, and the binding of small molecules requires proteins with pockets that match the shape of the ligand. For design of binding to symmetric ligands, protein homo-oligomers with matching symmetry are advantageous as each protein subunit can make identical interactions with the ligand. Here, we describe a general approach to designing hyperstable C2 symmetric proteins with pockets of diverse size and shape.

Portrayals of Pain in Children's Popular Media: Mothers' and Fathers' Beliefs and Attitudes.

Evidence suggests that children's popular media may model maladaptive and distorted experiences of pain to young children. In a recent study, pain depicted in popular media targeting 4-6-year-olds was frequently and unrealistically portrayed, evoked little response or empathy from observing characters, and perpetuated unhelpful gender stereotypes. Parents play a critical role in both children's pain experiences and children's media consumption.

Let's (Not) Talk About Pain: Mothers' and Fathers' Beliefs Regarding Reminiscing About Past Pain.

Children's memories for past pain set the stage for their future pain experiences. Parent-child reminiscing about pain plays a key role in shaping children's pain memories. Parental beliefs about the functions of reminiscing are associated with parental reminiscing behaviors.

Design of functionalised circular tandem repeat proteins with longer repeat topologies and enhanced subunit contact surfaces.

Circular tandem repeat proteins ('cTRPs') are de novo designed protein scaffolds (in this and prior studies, based on antiparallel two-helix bundles) that contain repeated protein sequences and structural motifs and form closed circular structures. They can display significant stability and solubility, a wide range of sizes, and are useful as protein display particles for biotechnology applications. However, cTRPs also demonstrate inefficient self-assembly from smaller subunits.

Structural basis for isoform-specific inhibition of human CTPS1.

Cytidine triphosphate synthase 1 (CTPS1) is necessary for an effective immune response, as revealed by severe immunodeficiency in CTPS1-deficient individuals [E. Martin ], [] [510], [288-292] ([2014]). CTPS1 expression is up-regulated in activated lymphocytes to expand CTP pools [E.

Reframe the Pain: A Randomized Controlled Trial of a Parent-Led Memory-Reframing Intervention.

Negatively-biased pain memories (ie, recalling more pain as compared to earlier reports) are a robust predictor of future pain experiences. This randomized controlled trial examined the efficacy of a memory-reframing intervention to reframe children's pain memories. Sixty-five children (54% girls, M=5.

Father- and Mother-Child Reminiscing About Past Pain and Young Children's Cognitive Skills.

Objective Painful experiences are common, distressing, and salient in childhood. Parent-child reminiscing about past painful experiences is an untapped opportunity to process pain-related distress and, similar to reminiscing about other distressing experiences, promotes children's broader development. Previous research has documented the role of parent-child reminiscing about past pain in children's pain-related cognitions (i.

The Socialization of Young Children's Empathy for Pain: The Role of Mother- and Father-Child Reminiscing.

Objective: Empathy for pain allows one to recognize, understand, and respond to another person's pain in a prosocial manner. Young children develop empathy for pain later than empathy for other negative emotions (e.g.

The sociocultural context of pediatric pain: an examination of the portrayal of pain in children's popular media.

Pain (eg, needle injections, injuries, and chronic pain) is highly prevalent in childhood and occurs in social contexts. Nevertheless, broader sociocultural influences on pediatric pain, such as popular media, have not been empirically examined. This study examined how pain is portrayed and gendered in children's popular media.

A Tie2 kinase mutation causing venous malformations increases phosphorylation rates and enhances cooperativity.

The endothelial receptor tyrosine kinase Tie2 plays an important role in vascular formation and maintenance. Mutations in Tie2 lead to vascular malformations, which are painful vascular lesions that cause disfigurement, bleeding, and thrombosis. R849W Tie2 is the most common mutation implicated in an inherited form of vascular malformations and has been shown to be activating, though little is known about the kinetic features of catalysis.

Molecular mechanisms of isocitrate dehydrogenase 1 (IDH1) mutations identified in tumors: The role of size and hydrophobicity at residue 132 on catalytic efficiency.

Isocitrate dehydrogenase 1 (IDH1) catalyzes the reversible NADP-dependent conversion of isocitrate (ICT) to α-ketoglutarate (αKG) in the cytosol and peroxisomes. Mutations in IDH1 have been implicated in >80% of lower grade gliomas and secondary glioblastomas and primarily affect residue 132, which helps coordinate substrate binding. However, other mutations found in the active site have also been identified in tumors.