Small-molecule-induced protein depletion technologies, also called inducible degrons, allow degradation of genetically engineered target proteins within cells and animals. Here, we design and develop the BromoTag, a new inducible degron system comprising a Brd4 bromodomain L387A variant as a degron tag that allows direct recruitment by heterobifunctional bumped proteolysis targeting chimeras (PROTACs) to hijack the VHL E3 ligase. We describe extensive optimization and structure–activity relationships of our bump-and-hole–PROTACs using a CRISPR knock-in cell line expressing model target BromoTag-Brd2 at endogenous levels. Collectively, our cellular and mechanistic data qualifies bumped PROTAC AGB1 as a potent, fast, and selective degrader of BromoTagged proteins, with a favorable pharmacokinetic profile in mice. The BromoTag adds to the arsenal of chemical genetic degradation tools allowing us to manipulate protein levels to interrogate the biological function and therapeutic potential in cells and in vivo .

Methanolic extracts of Anogeissus leiocarpus has been considered locally to have the same antimalarial activities as artemisinin derivatives. This work studied the in vivo antiplasmodial activity of methanolic extracts of A. leiocarpus and its effect on oxidative stress and lipid profile in mice infected with Plasmodium bergheii. Mice used for this study were divided into five groups; four of the groups were infected with P. bergheii. The first group was not infected with the parasite. The second group was infected with parasite but not treated with antimalarial drugs (negative control). The third group was infected and treated with artesunat at 5 mg/kg body weight (positive control), while the fourth and fifth groups were infected and treated with 100 and 200 mg/kg body weight of extract of stem bark of A. leiocarpus, respectively. The rate of parasite clearance was higher in the group treated with 200 mg/kg body weight of extract of A. leiocarpus when compared with the groups treated with artesunat. Malondialdehyde (MDA) level was significantly higher (P < 0.05) in the serum of negative control as compared with other groups which have received treatment. MDA level was moderately higher in the liver homogenates of infected mice treated with artesunat than in other groups. There were significant increases (P < 0.05) in the levels of serum and liver superoxide dismutase of infected mice treated with 200 mg/kg body weight of A. leiocarpus when compared with other groups. Serum low density lipoprotein, total triglyceride, and total cholesterol were moderately higher in the group treated with artesunat than other groups, while high density lipoprotein (HDL) level was higher in the two groups treated with A. leiocarpus as compared with the group treated with artesunat. This study shows that the methanolic extract of A. leiocarpus has high antimalarial activities, high antioxidant property, and capable of boosting HDL level in malaria-infected organisms.

The Golgi is a membrane-bound organelle that is essential for protein and lipid biosynthesis. It represents a central trafficking hub that sorts proteins and lipids to various destinations or for secretion from the cell. The Golgi has emerged as a docking platform for cellular signaling pathways including LRRK2 kinase whose deregulation leads to Parkinson disease. Golgi dysfunction is associated with a broad spectrum of diseases including cancer, neurodegeneration, and cardiovascular diseases. To allow the study of the Golgi at high resolution, we report a rapid Golgi immunoprecipitation technique (Golgi-IP) to isolate intact Golgi mini-stacks for subsequent analysis of their content. By fusing the Golgi-resident protein TMEM115 to three tandem HA epitopes (GolgiTAG), we purified the Golgi using Golgi-IP with minimal contamination from other compartments. We then established an analysis pipeline using liquid chromatography coupled with mass spectrometry to characterize the human Golgi proteome, metabolome, and lipidome. Subcellular proteomics confirmed known Golgi proteins and identified proteins not previously associated with the Golgi. Metabolite profiling established the human Golgi metabolome and revealed the enrichment of uridine-diphosphate (UDP) sugars and their derivatives, which is consistent with their roles in protein and lipid glycosylation. Furthermore, targeted metabolomics validated SLC35A2 as the subcellular transporter for UDP-hexose. Finally, lipidomics analysis showed that phospholipids including phosphatidylcholine, phosphatidylinositol, and phosphatidylserine are the most abundant Golgi lipids and that glycosphingolipids are enriched in this compartment. Altogether, our work establishes a comprehensive molecular map of the human Golgi and provides a powerful method to study the Golgi with high precision in health and disease.