Increased Absorption of Thyroxine in a Murine Model of Hypothyroidism Using Water/CO Nanobubbles.

Thyroxine (T4) is a drug extensively utilized for the treatment of hypothyroidism. However, the oral absorption of T4 presents certain limitations. This research investigates the efficacy of CO nanobubbles in water as a potential oral carrier for T4 administration to C57BL/6 hypothyroid mice.

Ca permeation through C-terminal cleaved, but not full-length human Pannexin1 hemichannels, mediates cell death.

Pannexin1 hemichannels (Panx1 HCs) are found in the membrane of most mammalian cells and communicate the intracellular and extracellular spaces, enabling the passive transfer of ions and small molecules. They are involved in physiological and pathophysiological conditions. During apoptosis, the C-terminal tail of Panx1 is proteolytically cleaved, but the permeability features of hemichannels and their role in cell death remain elusive.

Mechanism of voltage sensing in Ca- and voltage-activated K (BK) channels.

In neurosecretion, allosteric communication between voltage sensors and Ca binding in BK channels is crucially involved in damping excitatory stimuli. Nevertheless, the voltage-sensing mechanism of BK channels is still under debate. Here, based on gating current measurements, we demonstrate that two arginines in the transmembrane segment S4 (R210 and R213) function as the BK gating charges.

Endogenous pannexin1 channels form functional intercellular cell-cell channels with characteristic voltage-dependent properties.

The occurrence of intercellular channels formed by pannexin1 has been challenged for more than a decade. Here, we provide an electrophysiological characterization of exogenous human pannexin1 (hPanx1) cell–cell channels expressed in HeLa cells knocked out for connexin45. The observed hPanx1 cell–cell channels show two phenotypes: O-state and S-state.

The Emergence of New Catalytic Abilities in an Endoxylanase from Family GH10 by Removing an Intrinsically Disordered Region.

Endoxylanases belonging to family 10 of the glycoside hydrolases (GH10) are versatile in the use of different substrates. Thus, an understanding of the molecular mechanisms underlying substrate specificities could be very useful in the engineering of GH10 endoxylanases for biotechnological purposes. Herein, we analyzed XynA, an endoxylanase that contains a (β/α)-barrel domain and an intrinsically disordered region (IDR) of 29 amino acids at its amino end.

Unnexins: Homologs of innexin proteins in Trypanosomatidae parasites.

Large-pore channels, including those formed by connexin, pannexin, innexin proteins, are part of a broad family of plasma membrane channels found in vertebrates and invertebrates, which share topology features. Despite their relevance in parasitic diseases such as Chagas and malaria, it was unknown whether these large-pore channels are present in unicellular organisms. We identified 14 putative proteins in Trypanosomatidae parasites as presumptive homologs of innexin proteins.

A physiologic rise in cytoplasmic calcium ion signal increases pannexin1 channel activity via a C-terminus phosphorylation by CaMKII.

Pannexin1 (Panx1) channels are ubiquitously expressed in vertebrate cells and are widely accepted as adenosine triphosphate (ATP)-releasing membrane channels. Activation of Panx1 has been associated with phosphorylation in a specific tyrosine residue or cleavage of its C-terminal domains. In the present work, we identified a residue (S394) as a putative phosphorylation site by Ca/calmodulin-dependent kinase II (CaMKII).

Different Classes of Antidepressants Inhibit the Rat α7 Nicotinic Acetylcholine Receptor by Interacting within the Ion Channel: A Functional and Structural Study.

Several antidepressants inhibit nicotinic acetylcholine receptors (nAChRs) in a non-competitive and voltage-dependent fashion. Here, we asked whether antidepressants with a different structure and pharmacological profile modulate the rat α7 nAChR through a similar mechanism by interacting within the ion-channel. We applied electrophysiological (recording of the ion current elicited by choline, I, which activates α7 nAChRs from rat CA1 hippocampal interneurons) and in silico approaches (homology modeling of the rat α7 nAChR, molecular docking, molecular dynamics simulations, and binding free energy calculations).

Analysis of SARS-CoV-2 ORF3a structure reveals chloride binding sites.

SARS-CoV-2 ORF3a is believed to form ion channels, which may be involved in the modulation of virus release, and has been implicated in various cellular processes like the up-regulation of fibrinogen expression in lung epithelial cells, downregulation of type 1 interferon receptor, caspase-dependent apoptosis, and increasing IFNAR1 ubiquitination. ORF3a assemblies as homotetramers, which are stabilized by residue C133. A recent cryoEM structure of a homodimeric complex of ORF3a has been released.

Dynamin-2 R465W mutation induces long range perturbation in highly ordered oligomeric structures.

High order oligomers are crucial for normal cell physiology, and protein function perturbed by missense mutations underlies several autosomal dominant diseases. Dynamin-2 is one of such protein forming helical oligomers that catalyze membrane fission. Mutations in this protein, where R465W is the most frequent, cause dominant centronuclear myopathy, but the molecular mechanisms underpinning the functional modifications remain to be investigated.

The molecular nature of the 17β-Estradiol binding site in the voltage- and Ca-activated K (BK) channel β1 subunit.

The accessory β1 subunit modulates the Ca- and voltage-activated K (BK) channel gating properties mainly by increasing its apparent Ca sensitivity. β1 plays an important role in the modulation of arterial tone and blood pressure by vascular smooth muscle cells (SMCs). 17β-estradiol (E2) increases the BK channel open probability (P) in SMCs, through a β1 subunit-dependent modulatory effect.

Virtual Screening of Plant Volatile Compounds Reveals a High Affinity of Hylamorpha elegans (Coleoptera: Scarabaeidae) Odorant-Binding Proteins for Sesquiterpenes From Its Native Host.

Hylamorpha elegans(Burmeister) is a native Chilean scarab beetle considered to be a relevant agricultural pest to pasture and cereal and small fruit crops. Because of their cryptic habits, control with conventional methods is difficult; therefore, alternative and environmentally friendly control strategies are highly desirable. The study of proteins that participate in the recognition of odorants, such as odorant-binding proteins (OBPs), offers interesting opportunities to identify new compounds with the potential to modify pest behavior and computational screening of compounds, which is commonly used in drug discovery, may help to accelerate the discovery of new semiochemicals.