Control of molecular diffusion is pivotal for highly fluidic membranes to serve as substrates for biochemical reactions and the self-assembly of molecular machinery driving membrane protrusions. Lateral diffusion in membranes depends on lipid composition, which is highly diverse and homeostatically controlled in living cells. Due to the complexity of the underlying processes, its impact on molecular diffusion remain largely unclear. In this study, we show that lipid diffusion in model membranes is markedly decreased in cytosolic extracts. The reduction in lipid diffusivity could be pharmacologically inhibited by targeting phospholipase D (PLD), and addition of PLD to membranes mimicked the reduction in diffusion. Phosphatidic acid, a direct product of PLD, diffused slowly in model membranes and reduced the diffusivity of surrounding lipids. Furthermore, we demonstrated that PLD specifically controls the lateral diffusion of a myristoylated protein in cells, possibly due to auxiliary electrostatic interactions between cationic residues located near the lipidated tail and anionic phospholipids. PLD controlled the size and lifetime of localized patches of phosphatidylinositol (3,4,5)-trisphosphates that specify regions of membrane protrusions. Overall, the results of this study suggest that PLD controls the lateral diffusion of certain membrane proteins, which play key roles in phosphoinositide signaling.
See details in Honda et al. (2024) bioRxiv
Gen Honda, Chihuku Tanaka, Hidenori Hashimura, Tomoko Adachi, Mina Fujishiro, Nao Shimada, Satoshi Sawai, Miho Yanagisawa (2026) Phospholipase D regulates on-membrane diffusivity of a myristoylated protein and defines the PIP3 patch territory., Proceedings of the National Academy of Sciences of the United States of America, Volume 123, Number 20, pp. e2608790123
Published in May 13, 2026 (Electronic publication in May 13, 2026, midnight )
(Abstract) In living cells, the control of molecular diffusion is pivotal for highly fluidic membranes to serve as substrates for biochemical reactions and cytoskeletal assemblies. Lateral diffusion in membranes depends on a highly diverse and homeostatically controlled lipid composition. This complexity has limited our understanding of how diffusivity in biological membranes is regulated. In this study, we show that lipid diffusion in model membranes decreases markedly in the presence of cytosolic extracts. The reduction in lipid diffusivity can be pharmacologically inhibited by targeting phospholipase D (PLD). Conversely, lipid diffusivity was reduced when PLD alone was added to the membrane. Phosphatidic acid (PA), a direct product of PLD, diffuses slowly, and its presence reduces the diffusivity of surrounding lipids. Furthermore, we found that PLD controls the lateral diffusion of a myristoylated protein PKBR1 in Dictyostelium cells, possibly through auxiliary electrostatic interactions between cationic residues located near the lipidated tail and anionic phospholipids. In line with the role of PKBR1 in regulating phosphatidylinositol(3,4,5)-trisphosphates (PIP3), PLD overexpression suppressed the size and lifetime of PIP3 microdomains as well as the sensitivity of GPCR-mediated PIP3 elevation. Our results underscore the importance of PLD and its product PA as regulators of lipidated protein diffusivity, facilitating the dynamical lateral organization of phosphoinositides in the plasma membrane.(MeSH Terms)
Honda, Gen, Tanaka, Chihuku, Sawai, Satoshi, Yanagisawa, Miho (2024/01/01), Slow diffusion and signal amplification on membranes regulated by phospholipase D, bioRxiv, 2024.07.08.602473
Published in 2024/01/01
(Abstract) None