The rRNA mA methyltransferase METTL5 is involved in pluripotency and developmental programs.

Covalent chemical modifications of cellular RNAs directly impact all biological processes. However, our mechanistic understanding of the enzymes catalyzing these modifications, their substrates and biological functions, remains vague. Amongst RNA modifications N-methyladenosine (mA) is widespread and found in messenger (mRNA), ribosomal (rRNA), and noncoding RNAs.

Gallic acid sensitizes paclitaxel-resistant human ovarian carcinoma cells through an increase in reactive oxygen species and subsequent downregulation of ERK activation.

Paclitaxel (PTX) is currently used as a front-line chemotherapeutic agent for several types of cancer, including ovarian carcinoma; however, PTX-resistance frequently arises through multiple mechanisms. The development of new strategies using natural compounds and PTX in combination has been the aim of several prior studies, in order to enhance the efficacy of chemotherapy. In this study, we found the following: (i) gallic acid (GA), a phenolic compound, potentiated the capacity of PTX to decrease proliferation and to cause G2/M cycle arrest in the PTX-resistant A2780AD ovarian cancer cell line; (ii) GA exerted a pro-oxidant action by increasing the production of reactive oxygen species (ROS), and co-treatment with the antioxidant agent N‑acetyl-L‑cysteine (NAC) prevented GA+PTX-induced cell proliferation inhibition and G2/M phase arrest; (iii) PTX stimulated ERK phosphorylation/activation, and co-treatment with the MEK/ERK inhibitor PD98049 potentiated the proliferation inhibition and G2/M phase arrest; (iv) and finally, GA abrogated the PTX-induced stimulation of ERK phosphorylation, a response that was prevented by co-treatment with NAC.

Mice Lacking Endoglin in Macrophages Show an Impaired Immune Response.

Endoglin is an auxiliary receptor for members of the TGF-β superfamily and plays an important role in the homeostasis of the vessel wall. Mutations in endoglin gene (ENG) or in the closely related TGF-β receptor type I ACVRL1/ALK1 are responsible for a rare dominant vascular dysplasia, the Hereditary Hemorrhagic Telangiectasia (HHT), or Rendu-Osler-Weber syndrome. Endoglin is also expressed in human macrophages, but its role in macrophage function remains unknown.

L718P mutation in the membrane-proximal cytoplasmic tail of beta 3 promotes abnormal alpha IIb beta 3 clustering and lipid microdomain coalescence, and associates with a thrombasthenia-like phenotype.

Background: Support for the role of transmembrane and membrane-proximal domains of alpha IIb beta 3 integrin in the maintenance of receptor low affinity comes from mutational studies showing that activating mutations can induce constitutive bi-directional transmembrane signaling.

Design And Methods: We report the functional characterization of a mutant alpha IIb beta 3 integrin carrying the Leu718Pro mutation in the membrane-proximal region of the beta 3 cytoplasmic domain, identified in heterozygosis in a patient with a severe bleeding phenotype and defective platelet aggregation and adhesion.

Results: Transiently transfected cells expressed similar levels of normal and mutant alpha IIb beta 3, but surface expression of mutant alpha v beta 3 was reduced due to its retention in intracellular compartments.