The rockefeller university

In Trypanosoma brucei, genes are arranged in Polycistronic Transcription Units (PTUs), which are demarcated by transcription start and stop sites. Transcription start sites are also binding sites of Origin Recognition Complex 1 (ORC1). This spatial coincidence implies that transcription and replication in trypanosomes must occur in a highly ordered and cooperative manner. Interestingly, a previously published genetic screen identified the T. brucei MCM-BP, which interacts with subunits of MCM helicase, as a protein whose downregulation results in the loss of transcriptional silencing at subtelomeric loci. Here, I show that TbMCM-BP is required for DNA replication and transcription. TbMCM-BP depletion causes a significant reduction of replicating cells in S phase and genome-wide impairments of replication origin activation. Moreover, levels of sense and antisense transcripts increase at boundaries of PTUs in the absence of TbMCM-BP. TbMCM-BP is also important for transcriptional repression of the specialized subtelomeric PTUs, the Bloodstream-form Expression-Sites (BESs), which house the major antigenic determinant (the Variant Surface Glycoprotein, VSG gene) as well as TbORC1 binding sites. Overall, this study reveals that TbMCM-BP, a replication initiation protein, also guides the initiation, termination and directionality of transcription.

Deregulated WNT signaling has been shown to favor malignant transformation, tumor progression, and resistance to conventional cancer therapy in a variety of preclinical and clinical settings. Accumulating evidence suggests that aberrant WNT signaling may also subvert cancer immunosurveillance, hence promoting immunoevasion and resistance to multiple immunotherapeutics, including immune checkpoint blockers. Here, we discuss the molecular and cellular mechanisms through which WNT signaling influences cancer immunosurveillance and present potential therapeutic avenues to harness currently available WNT modulators for cancer immunotherapy.

Chemical probes of epigenetic 'readers' of histone post-translational modifications (PTMs) have become powerful tools for mechanistic and functional studies of their target proteins in normal physiology and disease pathogenesis. Here we report the development of the first class of chemical probes of YEATS domains, newly identified 'readers' of histone lysine acetylation (Kac) and crotonylation (Kcr). Guided by the structural analysis of a YEATS-Kcr complex, we developed a series of peptide-based inhibitors of YEATS domains by targeting a unique pi-pi-pi stacking interaction at the proteins' Kcr recognition site. Further structure optimization resulted in the selective inhibitors preferentially binding to individual YEATS-containing proteins including AF9 and ENL with submicromolar affinities. We demonstrate that one of the ENL YEATS-selective inhibitors, XL-13m, engages with endogenous ENL, perturbs the recruitment of ENL onto chromatin, and synergizes the BET and DOT1L inhibition-induced downregulation of oncogenes in MLL-rearranged acute leukemia.

The cystic fibrosis transmembrane conductance regulator ( CFTR) is an anion channel important in maintaining proper functions of the lung, pancreas, and intestine. The activity of CFTR is regulated by ATP and protein kinase A-dependent phosphorylation. To understand the conformational changes elicited by phosphorylation and ATP binding, we present here the structure of phosphorylated, ATP-bound human CFTR, determined by cryoelectronmicroscopy to 3.2-angstrom resolution. This structure reveals the position of the R domain after phosphorylation. By comparing the structures of human CFTR and zebrafish CFTR determined under the same condition, we identified common features essential to channel gating. The differences in their structures indicate plasticity permitted in evolution to achieve the same function. Finally, the structure of CFTR provides a better understanding of why the G178R, R352Q, L927P, and G970R/D mutations would impede conformational changes of CFTR and lead to cystic fibrosis.

The adaptive immune response generates a large repertoire of T cells with T-cell receptors (TCRalpha and TCR(bet)a) and B cells with immunoglobulins (Ig). The repertoire changes in response to antigen stimulation both through amplification of specific cells (clonal expansion) as well as somatic hypermutation of immunoglobulins. Alterations of the immune repertoire have been observed in response to acute disease, such as external pathogens, or chronic diseases, such as autoimmunity and cancer. Here we establish experimental and analytical protocols for quantifying the peripheral blood of healthy human individuals by profiling the immune repertoire for the Complementarity determining region 3 (CDR3) of the variable regions of TCRbeta. (CDR beta 3) and the IgG heavy chain (CDRH1, CDRH2, CDRH3). The results demonstrate that 40 ml of blood are sufficient to reliably capture the 10,000 most common TCRbeta. and 1000 most common IgG and determine their relative frequency in the circulation. We conclude that by using an accessible sample size of human PBMC one is able to robustly monitor alterations in the immune repertoire.

Corynebacterium bovis is an opportunistic bacterial pathogen shown to cause eye and prosthetic joint infections as well as abscesses in humans, mastitis in dairy cattle, and skin disease in laboratory mice and rats. Little is known about the genetic characteristics and genomic diversity of C. bovis because only a single draft genome is available for the species. The overall aim of this study was to sequence and compare the genome of C. bovis isolates obtained from different species, locations, and time points. Whole-genome sequencing was conducted on 20 C. bovis isolates (six human, four bovine, nine mouse and one rat) using the Illumina MiSeq platform and submitted to various comparative analysis tools. Sequencing generated high-quality contigs (over 2.53 Mbp) that were comparable to the only reported assembly using C. bovis DSM 20582(T) (97.8 +/- 0.36% completeness). The number of protein-coding DNA sequences (2,174 +/- 12.4) was similar among all isolates. A Corynebacterium genus neighbor-joining tree was created, which revealed Corynebacterium falsenii as the nearest neighbor to C. bovis (95.87% similarity), although the reciprocal comparison shows Corynebacterium jeikeium as closest neighbor to C. falsenii. Interestingly, the average nucleotide identity demonstrated that the C. bovis isolates clustered by host, with human and bovine isolates clustering together, and the mouse and rat isolates forming a separate group. The average number of genomic islands and putative virulence factors were significantly higher (p<0.001) in the mouse and rat isolates as compared to human/bovine isolates. Corynebacterium bovis' pan-genome contained a total of 3,067 genes of which 1,354 represented core genes. The known core genes of all isolates were primarily related to "metabolism" and "information storage/processing." However, most genes were classified as "function unknown" or "unclassified". Surprisingly, no intact prophages were found in any isolate; however, almost all isolates had at least one complete CRISPR-Cas system.

Characteristic lesions of the oral cavity in primary immunodeficiencies are commonly found in the form of periodontal disease, tooth decay and disorders of the oral mucosa. Humoral immunodeficiencies may cause tooth decay, while severe forms of plaque-induced periodontal disease are common in phagocytic deficiencies. The structural abnormalities of the teeth can occur in immunodeficiencies associated with apoptosis defect. Oral squamous cell carcinoma is a possible complication of immunodeficiencies associated with DNA repair defects.

Recent studies identify severely brain-injured patients with limited or no behavioral responses who successfully perform functional magnetic resonance imaging (fMRI) or electroencephalogram (EEG) mental imagery tasks [1-5]. Such tasks are cognitively demanding [1]; accordingly, recent studies support that fMRI command following in brain-injured patients associates with preserved cerebral metabolism and preserved sleep-wake EEG [5, 6]. We investigated the use of an EEG response that tracks the natural speech envelope (NSE) of spoken language [7-22] in healthy controls and brain-injured patients (vegetative state to emergence from minimally conscious state). As audition is typically preserved after brain injury, auditory paradigms may be preferred in searching for covert cognitive function [23-25]. NSE measures are obtained by cross-correlating EEG with the NSE. We compared NSE latencies and amplitudes with and without consideration of fMRI assessments. NSE latencies showed significant and progressive delay across diagnostic categories. Patients who could carry out fMRI-based mental imagery tasks showed no statistically significant difference in NSE latencies relative to healthy controls; this subgroup included patients without behavioral command following. The NSE may stratify patients with severe brain injuries and identify those patients demonstrating "cognitive motor dissociation" (CMD) [26] who show only covert evidence of command following utilizing neuroimaging or electrophysiological methods that demand high levels of cognitive function. Thus, the NSE is a passive measure that may provide a useful screening tool to improve detection of covert cognition with fMRI or other methods and improve stratification of patients with disorders of consciousness in research studies.

Low FMR1 variants (CGG(n<26)) have been associated with premature ovarian aging, female infertility and poor IVF treatment success. Until now, there is little published information concerning possible molecular mechanisms for this effect. We wished to examine whether relative expression of RNA and the FMR1 gene's fragile X mental retardation protein (FMRP) RNA isoforms differ in women with various FMR1 sub-genotypes (normal, low CGG(n<26) and/or high CGG(n >= 34)). This prospective cohort study was conducted between 2014 and 2017 in a clinical research unit of the Center for Human Reproduction in New York City. The study involved a total of 98 study subjects, including 18 young oocyte donors and 80 older infertility patients undergoing routine in vitro fertilization (IVF) cycles. The main outcome measure was RNA expression in human luteinized granulosa cells of 5 groups of FMRP isoforms. The relative expression of FMR1 RNA in human luteinized granulosa cells was measured by real-time PCR and a possible association with CGG(n) was explored. All 5 groups of FMRP RNA isoforms examined were found to be differentially expressed in human luteinized granulosa cells. The relative expression of four FMR1 RNA isoforms showed significant differences among 6 FMR1 sub-genotypes. Women with at least one low allele expressed significantly lower levels of all 5 sets of FRMP isoforms in comparison to the non-low group. While it would be of interest to see whether FMRP is also decreased in the low-group we recognize that in recent years it has been increasingly documented that information flow of genetics may be regulated by non-coding RNA, that is, without translation to a protein product. We, thus, conclude that various CGG expansions of FMR1 allele may lead to changes of RNA levels and ratios of distinct FMRP RNA isoforms, which could regulate the translation and/or cellular localization of FMRP, affect the expression of steroidogenic enzymes and hormonal receptors, or act in some other epigenetic process and therefore result in the ovarian dysfunction in infertility.

Next generation sequencing methods represent the latest era of molecular genetic diagnostics. After a general introduction on primary immunodeficiencies, the author summarizes the importance of molecular genetic studies, especially next generation sequencing in the diagnosis of primary immunodeficiencies. Another purpose of the manuscript is to give a brief summary on the methodological basis of next generation sequencing. The author analyzes the advantages and disadvantages of primary immunodeficiency gene-panel sequencing and whole-exome and wholegenome sequencing. Primary immunodeficiency genes and diseases recognized by next generation sequencing is also summarized. Finally, the author emphasizes the indispensability of gene level diagnostics in primary immunodeficiencies and presents the results achieved in this field in Hungary.