Spectroscopic Methods for Detecting Conformational Changes During Sec18-Lipid Interactions.

Vacuole fusion is driven by SNARE proteins that require activation-or priming-by the AAA+ protein Sec18 (NSF) before they can bring membranes together and trigger the merger of two bilayers into a continuous membrane. Sec18 resides on vacuoles prior to engaging inactive cis-SNARE complexes through its interaction with the regulatory lipid phosphatidic acid (PA). Binding PA causes Sec18 to undergo large conformational changes that keeps it bound to the membrane, thus precluding its interactions with SNAREs.

Use of Bio-Layer Interferometry (BLI) to Measure Binding Affinities of SNAREs and Phosphoinositides.

Bio-Layer Interferometry (BLI) is a technique that uses optical biosensing to analyze interactions between molecules. The analysis of molecular interactions is measured in real-time and does not require fluorescent tags. BLI uses disposable biosensors that come in a variety of formats to bind different ligands including biotin, hexahistidine, GST, and the Fc portion of antibodies.

Sphingolipids containing very long-chain fatty acids regulate Ypt7 function during the tethering stage of vacuole fusion.

Sphingolipids are essential in membrane trafficking and cellular homeostasis. Here, we show that sphingolipids containing very long-chain fatty acids (VLCFAs) promote homotypic vacuolar fusion in Saccharomyces cerevisiae. The elongase Elo3 adds the last two carbons to VLCFAs that are incorporated into sphingolipids.

The interdependent transport of yeast vacuole Ca and H and the role of phosphatidylinositol 3,5-bisphosphate.

Yeast vacuoles are acidified by the v-type H-ATPase (V-ATPase) that is comprised of the membrane embedded V complex and the soluble cytoplasmic V complex. The assembly of the V-V holoenzyme on the vacuole is stabilized in part through interactions between the V a-subunit ortholog Vph1 and the lipid phosphatidylinositol 3,5-bisphosphate (PI(3,5)P). PI(3,5)P also affects vacuolar Ca release through the channel Yvc1 and uptake through the Ca pump Pmc1.

High throughput analysis of vacuolar acidification.

Eukaryotic cells are compartmentalized into membrane-bound organelles, allowing each organelle to maintain the specialized conditions needed for their specific functions. One of the features that change between organelles is lumenal pH. In the endocytic and secretory pathways, lumenal pH is controlled by isoforms and concentration of the vacuolar-type H-ATPase (V-ATPase).

Napthoquinones from sp.-Antibiotic Activity against , the Causative Agent of Bacterial Fruit Blotch in Watermelon and Melon.

Bacterial fruit blotch (BFB) is a bacterial disease that devastates crops worldwide, causing significant economic losses. Currently, there is no means to treat or control the disease. This study focused on exploring the antibacterial properties of endophytic fungi against (), the causative agent of BFB.

Anionic nanoparticle-induced perturbation to phospholipid membranes affects ion channel function.

Understanding the mechanisms of nanoparticle interaction with cell membranes is essential for designing materials for applications such as bioimaging and drug delivery, as well as for assessing engineered nanomaterial safety. Much attention has focused on nanoparticles that bind strongly to biological membranes or induce membrane damage, leading to adverse impacts on cells. More subtle effects on membrane function mediated via changes in biophysical properties of the phospholipid bilayer have received little study.