Cooperation between PRMT1 and PRMT6 drives lung cancer health disparities among Black/African American men.

Lung cancer is the third most common cancer with Black/AA men showing higher risk and poorer outcomes than NHW men. Lung cancer disparities are multifactorial, driven by tobacco exposure, inequities in care access, upstream health determinants, and molecular determinants including biological and genetic factors. Elevated expressions of protein arginine methyltransferases (PRMTs) correlating with poorer prognosis have been observed in many cancers.

Role of histone variants H2BC1 and H2AZ.2 in H2AK119ub nucleosome organization and Polycomb gene silencing.

Ubiquitination of histone H2A at lysine 119 residue (H2AK119ub) plays critical roles in a wide range of physiological processes, including Polycomb gene silencing , replication , DNA damage repair , inactivation , and heterochromatin organization . However, the underlying mechanism and structural basis of H2AK119ub remains largely elusive. In this study, we report that H2AK119ub nucleosomes have a unique composition, containing histone variants H2BC1 and H2AZ.

MBD2a-NuRD binds to the methylated γ-globin gene promoter and uniquely forms a complex required for silencing of HbF expression.

During human development, there is a switch in the erythroid compartment at birth that results in silencing of expression of fetal hemoglobin (HbF). Reversal of this silencing has been shown to be effective in overcoming the pathophysiologic defect in sickle cell anemia. Among the many transcription factors and epigenetic effectors that are known to mediate HbF silencing, two of the most potent are BCL11A and MBD2-NuRD.

An unexpected second binding site for polypeptide substrates is essential for Hsp70 chaperone activity.

Heat shock proteins of 70 kDa (Hsp70s) are ubiquitous and highly conserved molecular chaperones. They play multiple essential roles in assisting with protein folding and maintaining protein homeostasis. Their chaperone activity has been proposed to require several rounds of binding to and release of polypeptide substrates at the substrate-binding domain (SBD) of Hsp70s.

Hyaluronic Acid Grafted Nanoparticles of a Platinum(II)-Silicon(IV) Phthalocyanine Conjugate for Tumor and Mitochondria-Targeted Photodynamic Therapy in Red Light.

Herein, we report novel hyaluronic acid formulated nanoparticles containing a platinum(II) conjugated silicon(IV) phthalocyanine (SiPc-Pt-HA) for tumor targeted red light photodynamic therapy and chemotherapy. The SiPc-Pt-HA conjugate showed specific uptake, photo-enhanced cytotoxicity (~1500 fold) and mitochondrial accumulation in breast cancer over normal cells.

WITHDRAWN: The chromatin remodeling complex NURF localizes to gene bodies and is required for mRNA processing.

This article has been withdrawn by Aiman Alhazmi, Marissa Mack, Tiffany Rolle, Jordan Hiegel, Syed Haqqani, Nga Dao, Farheen Zaman, Nak-Kyeong Kim, Neel Scarsdale, Charles Lyons, and Joseph Landry. Some of the genome-wide data sets were flawed and were not analyzed correctly. The withdrawing authors are in the process of correcting the data sets and re-analyzing them for resubmission.

Biophysical characterization of Aptenodytes forsteri cytochrome P450 aromatase.

Cytochrome P450 19 (CYP19, aromatase) catalyzes the conversion of androgens to estrogens in a sequence of three reactions that each depend on NADPH and O. Aromatase is a phylogenetically-ancient enzyme and its breadth of expression in other species has highlighted distinct physiological functions. In songbirds, estrogen production is required for programming the neural circuits controlling song and in the determination of sex in fish and reptiles.

Kinetics and inhibition studies of the L205R mutant of cAMP-dependent protein kinase involved in Cushing's syndrome.

Overproduction of cortisol by the hypothalamus-pituitary-adrenal hormone system results in the clinical disorder known as Cushing's syndrome. Genomics studies have identified a key mutation (L205R) in the α-isoform of the catalytic subunit of cAMP-dependent protein kinase (PKACα) in adrenal adenomas of patients with adrenocorticotropic hormone-independent Cushing's syndrome. Here, we conducted kinetics and inhibition studies on the L205R-PKACα mutant.

Human Papillomavirus E6 interaction with cellular PDZ domain proteins modulates YAP nuclear localization.

HPV E6 oncoproteins associate with cellular PDZ proteins. In addition to previously identified cellular PDZ proteins, we found association of the HPV16 E6 PBM with the Dystrophin Glycoprotein Complex, LRCC1, and SLC9A3R2. HPV18 E6 had additional associations when lysates from adenomatous cell lines were used including LRPPRC, RLGAPB, EIF3A, SMC2 and 3, AMOT, AMOTL1, and ARHGEF1; some of these cellular PDZ proteins are implicated in the regulation of the YAP1 transcriptional co-activator.

Characterization of PKACα enzyme kinetics and inhibition in an HPLC assay with a chromophoric substrate.

Here we describe a convenient, inexpensive, and non-hazardous method for the measurement of the kinase activity of the catalytic subunit of cAMP-dependent protein kinase (PKACα). The assay is based on the separation of a substrate peptide labeled with a strong chromophore from the phosphorylated product peptide by high-performance liquid chromatograph (HPLC) and quantification of the product ratiometrically at a wavelength in the visual spectrum (Vis). The utility and reliability of the HPLC-Vis assay were demonstrated by characterizing the kinetic parameters (K, V) of the new Rh-MAB-Kemptide substrate, a commercially prepared TAMRA-Kemptide substrate, and ATP as well as the potency (IC, K) of the known PKACα inhibitors H89 and PKI(5-24).

Understanding the Role and Impact of Effective Country and Community Leadership in Progress Toward the Global Plan.

Individual leadership and leaders have played pivotal roles in the history of efforts to end the AIDS epidemic. The goal of this article is to reflect on and understand how leadership and leaders have impacted and enabled the success of the Global Plan Towards the Elimination of New HIV Infections among Children by 2015 and Keeping their Mothers Alive (Global Plan). To accomplish this goal, multiple interviews were conducted with individuals in positions of leadership who had been identified as people whose actions drove progress.

N-Heterocyclic Carbene Capture by Cytochrome P450 3A4.

Cytochrome P450 3A4 (CYP3A4) is the dominant P450 enzyme involved in human drug metabolism, and its inhibition may result in adverse interactions or, conversely, favorably reduce the systemic elimination rates of poorly bioavailable drugs. Herein we describe a spectroscopic investigation of the interaction of CYP3A4 with N-methylritonavir, an analog of ritonavir, widely used as a pharmacoenhancer. In contrast to ritonavir, the binding affinity of N-methylritonavir for CYP3A4 is pH-dependent.

Design, synthesis, and in vitro evaluation of a fluorescently labeled irreversible inhibitor of the catalytic subunit of cAMP-dependent protein kinase (PKACα).

The design and development of irreversible kinase inhibitors is an expanding frontier of kinase drug discovery. The current approach to develop these inhibitors utilizes ATP-competitive inhibitor scaffolds to target non-catalytic cysteines in the kinase ATP-binding site. However, this approach is limited as not all kinases have a cysteine in the ATP-binding site that can be targeted.

Photoswitchable anticancer activity via trans-cis isomerization of a combretastatin A-4 analog.

Combretastatin A-4 (CA4) is highly potent anticancer drug that acts as an inhibitor of tubulin polymerization. The core of the CA4 structure contains a cis-stilbene, and it is known that the trans isomer is significantly less potent. We prepared an azobenzene analog of CA4 (Azo-CA4) that shows 13-35 fold enhancement in potency upon illumination.

Specific N-terminal cleavage of ribosomal protein L27 in Staphylococcus aureus and related bacteria.

Ribosomal protein L27 is a component of the eubacterial large ribosomal subunit that has been shown to play a critical role in substrate stabilization during protein synthesis. This function is mediated by the L27 N-terminus, which protrudes into the peptidyl transferase center. In this report, we demonstrate that L27 in Staphylococcus aureus and other Firmicutes is encoded with an N-terminal extension that is not present in most Gram-negative organisms and is absent from mature ribosomes.

Newly identified phosphorylation site in the vesicular stomatitis virus P protein is required for viral RNA synthesis.

The vesicular stomatitis virus (VSV) RNA-dependent RNA polymerase consists of two viral proteins; the large (L) protein is the main catalytic subunit, and the phosphoprotein (P) is an essential cofactor for polymerase function. The P protein interacts with the L protein and the N-RNA template, thus connecting the polymerase to the template. P protein also binds to free N protein to maintain it in a soluble, encapsidation-competent form.

Ending pediatric AIDS and achieving a generation born HIV-free.

In the 30 years of the AIDS pandemic, the devastating effects of HIV on infants and young children have often been overlooked and neglected. However, the ability to prevent mother-to-child transmission of HIV (PMTCT), or vertical transmission, has been one of the most significant prevention success stories in the global AIDS response. New HIV infections in children have been virtually eliminated in high-income countries and programmatic efforts have shifted to low-income and middle-income countries, particularly in sub-Saharan Africa, home to the vast majority of pediatric AIDS cases.

Paxillin enables attachment-independent tyrosine phosphorylation of focal adhesion kinase and transformation by RAS.

Paxillin and HIC5 are closely related adapter proteins that regulate cell migration and are tyrosine-phosphorylated by focal adhesion kinase (FAK). Paxillin, HIC5, and FAK tyrosine phosphorylation increase upon cell attachment and decrease upon detachment from extracellular matrix. Unexpectedly, we found that although FAK tyrosine phosphorylation in attached cells did not require paxillin, in detached fibroblasts there was remaining FAK tyrosine phosphorylation that required expression of paxillin and was not supported by HIC5.

PICquant: a quantitative platform to measure differential peptide abundance using dual-isotopic labeling with 12C6- and 13C6-phenyl isocyanate.

We have developed a complete system for the isotopic labeling, fractionation, and automated quantification of differentially expressed peptides that significantly facilitates candidate biomarker discovery. We describe a new stable mass tagging reagent pair, (12)C(6)- and (13)C(6)-phenyl isocyanate (PIC), that offers significant advantages over currently available tags. Peptides are labeled predominantly at their amino termini and exhibit elution profiles that are independent of label isotope.

MAZIE: a mass and charge inference engine to enhance database searching of tandem mass spectra.

Peptide sequence identification using tandem mass spectroscopy remains a major challenge for complex proteomic studies. Peptide matching algorithms require the accurate determination of both the mass and charge of the precursor ion and accommodate uncertainties in these properties by using a wide precursor mass tolerance and by testing, for each spectrum, several possible candidate charges. Using a data acquisition strategy that includes obtaining narrow mass-range MS(1) "zoom" scans, we describe here a post-acquisition algorithm dubbed mass and charge (Z) inference engine (MAZIE), which accurately determines the charge and monoisotopic mass of precursor ions on a low-resolution Thermo LTQ-XL mass spectrometer.

Nutrient isothiocyanates covalently modify and inhibit the inflammatory cytokine macrophage migration inhibitory factor (MIF).

Dietary ITCs (isothiocyanates) prevent cancer and show other bioactivities in vivo. As electrophiles, ITCs may covalently modify cellular proteins. Using a novel proteomics screen, we identified MIF (macrophage migration inhibitory factor) as the principal target of nutrient ITCs in intact cells.

Urokinase directly activates matrix metalloproteinases-9: a potential role in glioblastoma invasion.

Previous reports showed that urokinase plasminogen activator (uPA) converts plasminogen to plasmin which then activates matrix metalloproteinases (MMPs). Here, we report that uPA directly cleaved pro-MMP-9 in a time-dependent manner at both C- and N-terminus and generated two gelatinolytic bands. uPA-activated-MMP-9 efficiently degraded fibronectin and blocked by uPA inhibitor B428 and recombinant tissue inhibitor of metalloproteinase-1 (TIMP-1).