在阿斯加德古生物中的真核脂肪转移蛋白折叠的起源

Microbial membranes exhibit remarkable diversity in lipid composition, reflecting evolutionary adaptations to various environmental conditions. The three domains of life—Bacteria, Archaea, and Eukarya—synthesize membrane lipids through distinct biosynthetic pathways, leading to fundamental structural differences that impact membrane stability, function, and adaptability.Fatty Acid-Based Lipids in Bacteria and EukaryaBacteria and eukaryotes share a common fatty acid biosynthesis...

Biological membranes show uneven distribution of different types of lipids in the inner and outer layers, resulting in transverse asymmetric membranes. The treatment of the erythrocyte membrane with the enzyme phospholipase confirmed the asymmetric nature of the lipid bilayer. The enzyme hydrolyzes lipids into fatty acids and hydrophilic groups. The phospholipase acts only on the outer layer of the membrane, while the inner layer remains intact. The phospholipase treatment resulted in 80%...

The plasma membrane is an essential cellular structure responsible for maintaining cellular integrity and regulating the selective transport of molecules. While bacteria and archaea share the fundamental function of plasma membranes, their structural and molecular differences reflect adaptations to distinct ecological and physiological challenges.Bacterial Plasma MembranesBacterial plasma membranes are predominantly composed of phospholipids with fatty acid chains ester-linked to a glycerol...

In the plasma membrane, the lipids forming the bilayer can also act as an anchor to tether proteins to the membrane. The three main types of lipid anchors found in eukaryotes are – prenyl groups, fatty acyl groups, and glycosylphosphatidylinositol or GPI groups. Prenyl and fatty acyl groups act as anchors on the cytosolic surface of the membrane, whereas GPI anchors proteins on the extracellular side.
The carboxy-terminal of most of the prenylated proteins, such as Ras proteins, contains...

Biological membranes are more than just a barrier separating cell cytoplasm from the outside environment. They are highly dynamic and help maintain the integrity and physiological stability of the cells as well as membrane-bound organelles. Membranes also play vital roles in cell-to-cell and intracellular communication.
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...

Archaeal surface appendages are highly specialized structures essential for environmental adaptation, encompassing roles in adhesion, biofilm formation, and motility. Among these appendages, pili and archaella stand out for their distinct morphologies and functionalities, enabling archaea to thrive in diverse and often extreme environments.Pili: Adhesion and Biofilm FormationPili are filamentous structures assembled from pilin protein subunits, primarily contributing to adhesion and biofilm...