Melanin-Concentrating Hormone (MCH) is a cyclic peptide initially isolated from salmon and later found to be conserved in mammals. It plays a role in regulating melanin changes and rhythmic behaviors such as sleep and feeding, though its relationship with these processes is not fully understood. Our preliminary research revealed significant differences in melanin degradation in zebrafish under varying light conditions, suggesting a link to MCH. This study aims to explore MCH’s role in lighting-induced changes in rhythmic behavior patterns and melanin of zebrafish.

Sialylation plays important roles in animals, affecting numerous molecular and cell interactions. In Drosophila, sialylation regulates neural transmission and mediates communication between neurons and glia. Drosophila CMP-sialic acid synthetase (CSAS), a key enzyme of the sialylation pathway, is localized to the Golgi and modified by N-glycosylation, suggesting that this modification can affect CSAS function. Here we tested this hypothesis using in vitro and in vivo approaches. We found that CSAS proteins from divergent Drosophila species have two conserved N-glycosylation sites, including the rarely glycosylated non-canonical N-X-C sequon.

Atrial fibrillation (AF) involves electrical remodeling of the atria, with ion channels such as NaV1.5, KV1.5, and TASK-1 playing crucial roles. This study investigates acetamide-based compounds designed as multi-target inhibitors of these ion channels to address AF. Compound 6f emerged as the most potent in the series, demonstrating a strong inhibition of TASK-1 (IC50 ∼0.3 μM), a moderate inhibition of NaV1.5 (IC50 ∼21.2 μM) and a subtle inhibition of KV1.5 (IC50 ∼81.5 μM), alongside unexpected activation of TASK-4 (∼40% at 100 μM).

Mirtrons are a predominant class of noncanonical microRNAs derived from introns through a Drosha-independent, splicing-dependent pathway. Unregulated splicing of introns containing hairpins may adversely impact Dicer/Ago-mediated canonical microRNA biogenesis. However, the mechanism regulating mirtron biogenesis remains poorly understood. We found that the 5′ arm of plant mirtrons and invertebrate mirtrons are enriched for uracils; in contrast, the 5′ arm of vertebrate mirtrons are enriched for guanines.

Most adhesion G protein–coupled receptors (GPCRs) undergo autoproteolytic cleavage during receptor biosynthesis, resulting in noncovalently bound N-terminal fragments (NTFs) and C-terminal fragments (CTFs) that remain associated during receptor trafficking to the plasma membrane. While substantial evidence supports increased G protein signaling when just the CTF is expressed, there is an ongoing debate about whether NTF removal is required to initiate signaling in the context of the WT receptor.