POZ/BTB and AT hook containing zinc finger 1 (PATZ1) suppresses differentiation and regulates metabolism in human embryonic stem cells.

Human embryonic stem cells (hESCs) can proliferate infinitely (self-renewal) and give rise to almost all types of somatic cells (pluripotency). Hence, understanding the molecular mechanism of pluripotency regulation is important for applications of hESCs in regenerative medicine. Here we report that PATZ1 is a key factor that regulates pluripotency and metabolism in hESCs. We found that depletion of PATZ1 is associated with rapid downregulation of master pluripotency genes and prominent deceleration of cell growth. We also revealed that PATZ1 regulates hESC pluripotency though binding the regulatory regions of OCT4 and NANOG. In addition, we demonstrated PATZ1 is a key node in the OCT4/NANOG transcriptional network. We further revealed that PATZ1 is essential for cell growth in hESCs. Importantly, we discovered that depletion of PATZ1 drives hESCs to exploit glycolysis which energetically compensates for the mitochondrial dysfunction. Overall, our study establishes the fundamental role of PATZ1 in regulating pluripotency in hESCs. Moreover, PATZ1 is essential for maintaining a steady metabolic homeostasis to refine the stemness of hESCs.

Analysis of whiB7 in Mycobacterium tuberculosis reveals novel AT-hook deletion mutations.

Mutations in whiB7 have been associated with both hypersusceptibility and resistance to various antibiotics in Mycobacterium tuberculosis (Mtb). Unlocking the secrets of antibiotic resistance in the bacterium, we examined mutations in the coding sequences of whiB7 of over 40,000 diverse Mtb isolates. Our results unveil the dominant c.191delG (Gly64delG) mutation, present in all members of the lineage L1.2.2 and its impact on WhiB7's conserved GVWGG-motif, causing conformational changes and deletion of the C-terminal AT-hook. Excitingly, we discovered six unique mutations associated with partial or total deletion of the AT-hook, specific to certain sublineages. Our findings suggest the selective pressures driving these mutations, underlining the potential of genomics to advance our understanding of Mtb's antibiotic resistance. As tuberculosis remains a global health threat, our study offers valuable insights into the diverse nature and functional consequences of whiB7 mutations, paving the way for the development of novel therapeutic interventions.

Systematical Characterization of the AT-Hook Gene Family in Juglans regia L. and the Functional Analysis of the JrAHL2 in Flower Induction and Hypocotyl Elongation.

AT-hook motif nuclear localization (AHL) proteins play essential roles in various plant biological processes. Yet, a comprehensive understanding of AHL transcription factors in walnut (Juglans regia L.) is missing. In this study, 37 AHL gene family members were first identified in the walnut genome. Based on the evolutionary analysis, JrAHL genes were grouped into two clades, and their expansion may occur due to segmental duplication. The stress-responsive nature and driving of developmental activities of JrAHL genes were revealed by cis-acting elements and transcriptomic data, respectively. Tissue-specific expression analysis showed that JrAHLs had a profound transcription in flower and shoot tip, JrAHL2 in particular. Subcellular localization showed that JrAHL2 is anchored to the nucleus. Overexpression of JrAHL2 in Arabidopsis adversely affected hypocotyl elongation and delayed flowering. Our study, for the first time, presented a detailed analysis of JrAHL genes in walnut and provided theoretical knowledge for future genetic breeding programs.

AT-HOOK MOTIF NUCLEAR LOCALIZED (AHL) proteins of ancient origin radiate new functions.

AHL (AT-HOOK MOTIF NUCLEAR LOCALIZED) protein is an important transcription factor in plants that regulates a wide range of biological process. It is considered to have evolved from an independent PPC domain in prokaryotes to a complete protein in modern plants. AT-hook motif and PPC conserved domains are the main functional domains of AHL. Since the discovery of AHL, their evolution and function have been continuously studied. The AHL gene family has been identified in multiple species and the functions of several members of the gene family have been studied. Here, we summarize the evolution and structural characteristics of AHL genes, and emphasize their biological functions. This review will provide a basis for further functional study and crop breeding.

AT-hook peptides bind the major and minor groove of AT-rich DNA duplexes.

The mammalian high mobility group protein AT-hook 2 (HMGA2) houses three motifs that preferentially bind short stretches of AT-rich DNA regions. These DNA binding motifs, known as 'AT-hooks', are traditionally characterized as being unstructured. Upon binding to AT-rich DNA, they form ordered assemblies. It is this disordered-to-ordered transition that has implicated HMGA2 as a protein actively involved in many biological processes, with abnormal HMGA expression linked to a variety of health problems including diabetes, obesity, and oncogenesis. In the current work, the solution binding dynamics of the three 'AT-hook' peptides (ATHPs) with AT-rich DNA hairpin substrates were studied using DNA UV melting studies, fluorescence spectroscopy, native ion mobility spectrometry-mass spectrometry (IMS-MS), solution isothermal titration calorimetry (ITC) and molecular modeling. Results showed that the ATHPs bind to the DNA to form a single, 1:1 and 2:1, 'key-locked' conformational ensemble. The molecular models showed that 1:1 and 2:1 complex formation is driven by the capacity of the ATHPs to bind to the minor and major grooves of the AT-rich DNA oligomers. Complementary solution ITC results confirmed that the 2:1 stoichiometry of ATHP: DNA is originated under native conditions in solution.

Transcriptomic-Based Identification of the Immuno-Oncogenic Signature of Cholangiocarcinoma for HLC-018 Multi-Target Therapy Exploration.

Cholangiocarcinomas (CHOLs), hepatobiliary malignancies, are characterized by high genetic heterogeneity, a rich tumor microenvironment, therapeutic resistance, difficulty diagnosing, and poor prognoses. Current knowledge of genetic alterations and known molecular markers for CHOL is insufficient, necessitating the need for further evaluation of the genome and RNA expression data in order to identify potential therapeutic targets, clarify the roles of these targets in the tumor microenvironment, and explore novel therapeutic drugs against the identified targets. Consequently, in our attempt to explore novel genetic markers associated with the carcinogenesis of CHOL, five genes (SNX15, ATP2A1, PDCD10, BET1, and HMGA2), collectively termed CHOL-hub genes, were identified via integration of differentially expressed genes (DEGs) from relatively large numbers of samples from CHOL GEO datasets. We further explored the biological functions of the CHOL-hub genes and found significant enrichment in several biological process and pathways associated with stem cell angiogenesis, cell proliferation, and cancer development, while the interaction network revealed high genetic interactions with a number of onco-functional genes. In addition, we established associations between the CHOL-hub genes and tumor progression, metastasis, tumor immune and immunosuppressive cell infiltration, dysfunctional T-cell phenotypes, poor prognoses, and therapeutic resistance in CHOL. Thus, we proposed that targeting CHOL-hub genes could be an ideal therapeutic approach for treating CHOLs, and we explored the potential of HLC-018, a novel benzamide-linked small molecule, using molecular docking of ligand-receptor interactions. To our delight, HLC-018 was well accommodated with high binding affinities to binding pockets of CHOL-hub genes; more importantly, we found specific interactions of HLC-018 with the conserved sequence of the AT-hook DNA-binding motif of HMGA2. Altogether, our study provides insights into the immune-oncogenic phenotypes of CHOL and provides valuable information for our ongoing experimental validation.

The Trithorax group protein ASH1 requires a combination of BAH domain and AT hooks, but not the SET domain, for mitotic chromatin binding and survival.

The Drosophila Trithorax group (TrxG) protein ASH1 remains associated with mitotic chromatin through mechanisms that are poorly understood. ASH1 dimethylates histone H3 at lysine 36 via its SET domain. Here, we identify domains of the TrxG protein ASH1 that are required for mitotic chromatin attachment in living Drosophila. Quantitative live imaging demonstrates that ASH1 requires AT hooks and the BAH domain but not the SET domain for full chromatin binding in metaphase, and that none of these domains are essential for interphase binding. Genetic experiments show that disruptions of the AT hooks and the BAH domain together, but not deletion of the SET domain alone, are lethal. Transcriptional profiling demonstrates that intact ASH1 AT hooks and the BAH domain are required to maintain expression levels of a specific set of genes, including several involved in cell identity and survival. This study identifies in vivo roles for specific ASH1 domains in mitotic binding, gene regulation, and survival that are distinct from its functions as a histone methyltransferase.

Characteristics of the AT-Hook Motif Containing Nuclear Localized (AHL) Genes in Carrot Provides Insight into Their Role in Plant Growth and Storage Root Development.

The AT-hook motif containing nuclear localized (AHL) gene family, controlling various developmental processes, is conserved in land plants. They comprise Plant and Prokaryote Conserved (PPC) domain and one or two AT-hook motifs. DcAHLc1 has been proposed as a candidate gene governing the formation of the carrot storage root. We identified and in-silico characterized carrot AHL proteins, performed phylogenetic analyses, investigated their expression profiles and constructed gene coexpression networks. We found 47 AHL genes in carrot and grouped them into two clades, A and B, comprising 29 and 18 genes, respectively. Within Clade-A, we distinguished three subclades, one of them grouping noncanonical AHLs differing in their structure (two PPC domains) and/or cellular localization (not nucleus). Coexpression network analysis attributed AHLs expressed in carrot roots into four of the 72 clusters, some of them showing a large number of interactions. Determination of expression profiles of AHL genes in various tissues and samples provided basis to hypothesize on their possible roles in the development of the carrot storage root. We identified a group of rapidly evolving noncanonical AHLs, possibly differing functionally from typical AHLs, as suggested by their expression profiles and their predicted cellular localization. We pointed at several AHLs likely involved in the development of the carrot storage root.

Genome-wide identification and expression analysis of the AT-hook Motif Nuclear Localized gene family in soybean.

BACKGROUND: Soybean is an important legume crop and has significant agricultural and economic value. Previous research has shown that the AT-Hook Motif Nuclear Localized (AHL) gene family is highly conserved in land plants, playing crucial roles in plant growth and development. To date, however, the AHL gene family has not been studied in soybean. RESULTS: To investigate the roles played by the AHL gene family in soybean, genome-wide identification, expression patterns and gene structures were performed to analyze. We identified a total of 63 AT-hook motif genes, which were characterized by the presence of the AT-hook motif and PPC domain in soybean. The AT-hook motif genes were distributed on 18 chromosomes and formed two distinct clades (A and B), as shown by phylogenetic analysis. All the AHL proteins were further classified into three types (I, II and III) based on the AT-hook motif. Type-I was belonged to Clade-A, while Type-II and Type-III were belonged to Clade-B. Our results also showed that the main type of duplication in the soybean AHL gene family was segmented duplication event. To discern whether the AHL gene family was involved in stress response in soybean, we performed cis-acting elements analysis and found that AHL genes were associated with light responsiveness, anaerobic induction, MYB and gibberellin-responsiveness elements. This suggest that AHL genes may participate in plant development and mediate stress response. Moreover, a co-expression network analysis showed that the AHL genes were also involved in energy transduction, and the associated with the gibberellin pathway and nuclear entry signal pathways in soybean. Transcription analysis revealed that AHL genes in Jack and Williams82 have a common expression pattern and are mostly expressed in roots, showing greater sensitivity under drought and submergence stress. Hence, the AHL gene family mainly reacts on mediating stress responses in the roots and provide comprehensive information for further understanding of the AT-hook motif gene family-mediated stress response in soybean. CONCLUSION: Sixty-three AT-hook motif genes were identified in the soybean genome. These genes formed into two distinct phylogenetic clades and belonged to three different types. Cis-acting elements and co-expression network analyses suggested that AHL genes participated in significant biological processes. This work provides important theoretical basis for the understanding of AHLs biological functions in soybean.

An Arabidopsis AT-hook motif nuclear protein mediates somatic embryogenesis and coinciding genome duplication.

Plant somatic cells can be reprogrammed into totipotent embryonic cells that are able to form differentiated embryos in a process called somatic embryogenesis (SE), by hormone treatment or through overexpression of certain transcription factor genes, such as BABY BOOM (BBM). Here we show that overexpression of the AT-HOOK MOTIF CONTAINING NUCLEAR LOCALIZED 15 (AHL15) gene induces formation of somatic embryos on Arabidopsis thaliana seedlings in the absence of hormone treatment. During zygotic embryogenesis, AHL15 expression starts early in embryo development, and AH15 and other AHL genes are required for proper embryo patterning and development beyond the globular stage. Moreover, AHL15 and several of its homologs are upregulated and required for SE induction upon hormone treatment, and they are required for efficient BBM-induced SE as downstream targets of BBM. A significant number of plants derived from AHL15 overexpression-induced somatic embryos are polyploid. Polyploidisation occurs by endomitosis specifically during the initiation of SE, and is caused by strong heterochromatin decondensation induced by AHL15 overexpression.

Chromatin phosphoproteomics unravels a function for AT-hook motif nuclear localized protein AHL13 in PAMP-triggered immunity.

In many eukaryotic systems during immune responses, mitogen-activated protein kinases (MAPKs) link cytoplasmic signaling to chromatin events by targeting transcription factors, chromatin remodeling complexes, and the RNA polymerase machinery. So far, knowledge on these events is scarce in plants and no attempts have been made to focus on phosphorylation events of chromatin-associated proteins. Here we carried out chromatin phosphoproteomics upon elicitor-induced activation of Arabidopsis The events in WT were compared with those in mpk3, mpk4, and mpk6 mutant plants to decipher specific MAPK targets. Our study highlights distinct signaling networks involving MPK3, MPK4, and MPK6 in chromatin organization and modification, as well as in RNA transcription and processing. Among the chromatin targets, we characterized the AT-hook motif containing nuclear localized (AHL) DNA-binding protein AHL13 as a substrate of immune MAPKs. AHL13 knockout mutant plants are compromised in pathogen-associated molecular pattern (PAMP)-induced reactive oxygen species production, expression of defense genes, and PAMP-triggered immunity. Transcriptome analysis revealed that AHL13 regulates key factors of jasmonic acid biosynthesis and signaling and affects immunity toward Pseudomonas syringae and Botrytis cinerea pathogens. Mutational analysis of the phosphorylation sites of AHL13 demonstrated that phosphorylation regulates AHL13 protein stability and thereby its immune functions.

The Class III peroxidase gene OsPrx30, transcriptionally modulated by the AT-hook protein OsATH1, mediates rice bacterial blight-induced ROS accumulation.

Class III peroxidases (CIII Prxs) play critical roles in plant immunity by scavenging reactive oxygen species (ROS). However, the functions of CIII Prxs in rice (Oryza sativa L.) immunity are largely unexplored. Here, we report a Prx precursor, OsPrx30, that is responsive to the bacterial blight Xanthomonas oryzae pv. oryzae (Xoo). OsPrx30 was primarily expressed in rice roots, leaves, and stems, and its protein product was mainly localized at the endoplasmic reticulum. Overexpression of OsPrx30 enhanced the plant's susceptibility to Xoo by maintaining a high level of peroxidase (POD) activity and reducing the content of H2 O2 , whereas depletion of OsPrx30 had the opposite effects. Furthermore, we identified an AT-hook transcription factor, OsATH1, that is specifically bound to the OsPrx30 promoter. As observed in plants overexpressing OsPrx30, depletion of OsATH1 enhanced susceptibility to Xoo. Finally, we demonstrated that depletion of OsATH1 increased histone H3 acetylation at the AT-rich region of the OsPrx30 promoter. Taken together, these results reveal a mechanism underlying the POD-induced natural resistance to bacterial diseases and suggest a model for transcription regulation of Prx genes in rice.

Phase-Separated Transcriptional Condensates Accelerate Target-Search Process Revealed by Live-Cell Single-Molecule Imaging.

Compartmentalization by liquid-liquid phase separation is implicated in transcription. It remains unclear whether and how transcriptional condensates accelerate the search of transcriptional regulatory factors for their target sites. Furthermore, the molecular mechanisms by which regulatory factors nucleate on chromatin to assemble transcriptional condensates remain incompletely understood. The CBX-PRC1 complexes compartmentalize key developmental regulators for repression through phase-separated condensates driven by the chromobox 2 (CBX2) protein. Here, by using live-cell single-molecule imaging, we show that CBX2 nucleates on chromatin independently of H3K27me3 and CBX-PRC1. The interactions between CBX2 and DNA are essential for nucleating CBX-PRC1 on chromatin to assemble condensates. The assembled condensates shorten 3D diffusion time and reduce trials for finding specific sites through revisiting the same or adjacent sites repetitively, thereby accelerating CBX2 in searching for target sites. Overall, our data suggest a generic mechanism by which transcriptional regulatory factors nucleate to assemble condensates that accelerate their target-search process.

A suppressor of axillary meristem maturation promotes longevity in flowering plants.

Post-embryonic development and longevity of flowering plants are, for a large part, determined by the activity and maturation state of stem cell niches formed in the axils of leaves, the so-called axillary meristems (AMs)1,2. The genes that are associated with AM maturation and underlie the differences between monocarpic (reproduce once and die) annual and the longer-lived polycarpic (reproduce more than once) perennial plants are still largely unknown. Here we identify a new role for the Arabidopsis AT-HOOK MOTIF NUCLEAR LOCALIZED 15 (AHL15) gene as a suppressor of AM maturation. Loss of AHL15 function accelerates AM maturation, whereas ectopic expression of AHL15 suppresses AM maturation and promotes longevity in monocarpic Arabidopsis and tobacco. Accordingly, in Arabidopsis grown under longevity-promoting short-day conditions, or in polycarpic Arabidopsis lyrata, expression of AHL15 is upregulated in AMs. Together, our results indicate that AHL15 and other AHL clade-A genes play an important role, directly downstream of flowering genes (SOC1, FUL) and upstream of the flowering-promoting hormone gibberellic acid, in suppressing AM maturation and extending the plant's lifespan.

At-Hook Motif Nuclear Localised Protein 18 as a Novel Modulator of Root System Architecture.

The At-Hook Motif Nuclear Localized Protein (AHL) gene family encodes embryophyte-specific nuclear proteins with DNA binding activity. They modulate gene expression and affect various developmental processes in plants. We identify AHL18 (At3G60870) as a developmental modulator of root system architecture and growth. AHL18 is involved in regulation of the length of the proliferation domain and number of dividing cells in the root apical meristem and thereby, cell production. Both primary root growth and lateral root development respond according to AHL18 transcription level. The ahl18 knock-out plants show reduced root systems due to a shorter primary root and a lower number of lateral roots. This change results from a higher number of arrested and non-developing lateral root primordia (LRP) rather than from a decreased LRP initiation. The over-expression of AHL18 results in a more extensive root system, longer primary roots, and increased density of lateral root initiation events. AHL18 is thus involved in the formation of lateral roots at both LRP initiation and their later development. We conclude that AHL18 participates in modulation of root system architecture through regulation of root apical meristem activity, lateral root initiation and emergence; these correspond well with expression pattern of AHL18.

Genome-wide identification, expression profiling, and network analysis of AT-hook gene family in maize.

AT-hook motif nuclear localized (AHL) genes have diverse but poorly understood biological functions. We identified and analyzed 37 AHL genes in maize. We also discovered four and one additional AHLs in rice and sorghum, respectively, besides those reported earlier. The maize AHLs were classified into two clades (A and B) and three distinct types (I, II, and III) as also reported in Arabidopsis. Phylogenetic and ortholog analyses showed that, while the evolutionary classification was conserved in plants, expansion of the AHL gene family in maize was accompanied with new biological functions. Gene structure analysis showed that, while all but one Type-I AHLs lacked an intron, origin of Type-II and Type-III AHLs was associated with the gain of introns suggesting evolutionarily distinct temporal and spatial expression patterns and, likely, neofunctionalization. Gene duplication analysis revealed that AHLs in maize expanded via dispersive duplication further supporting their functional diversity. To discern these functions, we analyzed 71 transcriptomes from diverse tissues and developmental stages of maize and classified AHLs into eight groups with distinct temporal/spatial expression profiles. Coexpression analysis implicated 5 AHLs and 33 novel genes in networks specific to endosperm, seed, root, leaf, and reproductive tissues indicating their role in the development of these organs. Major processes coregulated by AHLs include pollen development, drought response, senescence, and wound response. We also identified interactions of AHL proteins in coregulating important processes including stress response. These novel insights into the role of AHLs in plant development provide a platform for functional analyses in maize and related grasses.

PERSISTENT TAPETAL CELL2 Is Required for Normal Tapetal Programmed Cell Death and Pollen Wall Patterning.

The timely programmed cell death (PCD) of the tapetum, the innermost somatic anther cell layer in flowering plants, is critical for pollen development, including the deposition and patterning of the pollen wall. Although several genes involved in tapetal PCD and pollen wall development have been characterized, the underlying regulatory mechanism remains elusive. Here we report that PERSISTENT TAPETAL CELL2 (PTC2), which encodes an AT-hook nuclear localized protein in rice (Oryza sativa), is required for normal tapetal PCD and pollen wall development. The mutant ptc2 showed persistent tapetal cells and abnormal pollen wall patterning including absent nexine, collapsed bacula, and disordered tectum. The defective tapetal PCD phenotype of ptc2 was similar to that of a PCD delayed mutant, ptc1, in rice, while the abnormal pollen wall patterning resembled that of a pollen wall defective mutant, Transposable Element Silencing Via AT-Hook, in Arabidopsis (Arabidopsis thaliana). Levels of anther cutin monomers in ptc2 anthers were significantly reduced, as was expression of a series of lipid biosynthetic genes. PTC2 transcript and protein were shown to be present in the anther after meiosis, consistent with the observed phenotype. Based on these data, we propose a model explaining how PTC2 affects anther and pollen development. The characterization of PTC2 in tapetal PCD and pollen wall patterning expands our understanding of the regulatory network of male reproductive development in rice and will aid future breeding approaches.

Promotion of adipogenesis by JMJD6 requires the AT hook-like domain and is independent of its catalytic function.

JMJD6 is a member of the Jumonji C domain containing enzymes that demethylate and/or hydroxylate substrate proteins. It is a multi-functional protein that has been implicated in disparate aspects of transcriptional and post-transcriptional control of gene expression, including but not limited to enhancer and promoter binding, release of paused RNA polymerase II, control of splicing, and interaction with the translation machinery. JMJD6 contributes to multiple aspects of animal development, including adipogenesis modeled in culture. We mutated proposed or characterized domains in the JMJD6 protein to better understand the requirement for JMJD6 in adipogenic differentiation. Mutation of JMJD6 amino acids that mediate binding of iron and 2-oxogluterate, which are required cofactors for enzymatic activity, had no impact on JMJD6 function, showing that catalytic activity is not required for JMJD6 contributions to adipogenic differentiation. In addition, we documented the formation of JMJD6 oligomers and showed that catalytic activity is not required for oligomerization, as has been reported previously. We also observed no effect of mutations in the sumoylation site and in the poly-serine stretch. In contrast, mutation of the AT hook-like structure, which mediates interaction with DNA and/or RNA, compromised JMJD6 function by blocking its ability to interact with chromatin at genes that express regulators of adipogenesis. The ability of JMJD6 to interact with nucleic acids may be a critical requirement for its function in adipogenic differentiation. The requirement for the AT hook-like domain and the lack of requirement for catalytic activity giving rise to the idea that co-activation of transcription by JMJD6 may be functioning as a scaffold protein that supports the interactions of other critical regulators.

AKNA Frameshift Variant in Three Dogs with Recurrent Inflammatory Pulmonary Disease.

We investigated three related Rough Collies with recurrent inflammatory pulmonary disease. The clinical symptoms were similar to primary ciliary dyskinesia (PCD). However, the affected dogs did not carry any known pathogenic PCD variants. Pedigree analysis suggested a recessive mode of inheritance. Combined linkage and homozygosity mapping in three cases and seven non-affected family members delineated 19 critical intervals on 10 chromosomes comprising a total of 99 Mb. The genome of one affected dog was sequenced and compared to 601 control genomes. We detected only a single private homozygous protein-changing variant in the critical intervals. The detected variant was a 4 bp deletion, c.2717_2720delACAG, in the AKNA gene encoding the AT-hook transcription factor. It causes a frame-shift introducing a premature stop codon and truncates 37% of the open reading frame, p.(Asp906Alafs*173). We genotyped 88 Rough Collies consisting of family members and unrelated individuals. All three available cases were homozygous for the mutant allele and all 85 non-affected dogs were either homozygous wildtype (n = 67) or heterozygous (n = 18). AKNA modulates inflammatory immune responses. Akna-/- knockout mice die shortly after birth due to systemic autoimmune inflammatory processes including lung inflammation that is accompanied by enhanced leukocyte infiltration and alveolar destruction. The perfect genotype-phenotype association and the comparative functional data strongly suggest that the detected AKNA:c.2717_2720delACAG variant caused the observed severe airway inflammation in the investigated dogs. Our findings enable genetic testing, which can be used to avoid the unintentional breeding of affected puppies.

Comparative Study of Photoswitchable Zinc-Finger Domain and AT-Hook Motif for Light-Controlled Peptide-DNA Binding.

DNA-peptide interactions are involved in key life processes, including DNA recognition, replication, transcription, repair, organization, and modification. Development of tools that can influence DNA-peptide binding non-invasively with high spatiotemporal precision could aid in determining its role in cells and tissues. Here, the design, synthesis, and study of photocontrolled tools for sequence-specific small peptide-DNA major and minor groove interactions are reported, shedding light on DNA binding by transcriptionally active peptides. In particular, photoswitchable moieties were implemented in the peptide backbone or turn region. In each case, DNA binding was affected by photochemical isomerization, as determined in fluorescent displacement assays on model DNA strands, which provides promising tools for DNA modulation.