Transient GPI-anchored protein homodimers are units for raft organization and function

Suzuki, Kenichi; Kasai, Rinshi S.; Hirosawa, K; Nemoto, Yukio; Ishibashi, Mana; Miwa, Yoshiro; Fujiwara, Takeshi; Kusumi, Akihiro

doi:10.1038/nchembio.1028

Cited by 239 publications

(280 citation statements)

References 50 publications

Supporting

Mentioning

256

Contrasting

Unclassified

Order By: Relevance

“…This suggests that the dynamic creation and destruction of lipid nanodomains might indeed be a key modulator of protein signaling. One example is the dimerization of GPI-anchored receptors taking place on the timescale of several hundred milliseconds, where dimerization is altered by raft-lipid interactions (35). To our knowledge, our measurements represent the first step in exploiting iSCAT to provide a quantitative understanding of the role of nanoscopic lipid phase separation in membrane signaling.…”

Section: Discussionmentioning

confidence: 95%

Dynamic label-free imaging of lipid nanodomains

Wit

Danial

Kukura

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

100

View full text Add to dashboard Cite

Lipid rafts are submicron proteolipid domains thought to be responsible for membrane trafficking and signaling. Their small size and transient nature put an understanding of their dynamics beyond the reach of existing techniques, leading to much contention as to their exact role. Here, we exploit the differences in light scattering from lipid bilayer phases to achieve dynamic imaging of nanoscopic lipid domains without any labels. Using phase-separated droplet interface bilayers we resolve the diffusion of domains as small as 50 nm in radius and observe nanodomain formation, destruction, and dynamic coalescence with a domain lifetime of 220 ± 60 ms. Domain dynamics on this timescale suggests an important role in modulating membrane protein function.droplet interface bilayer | iSCAT | lipid nanodomains | label-free imaging | light scattering C ell membranes compartmentalize into lipid domains that enable the selective recruitment of specific proteins (1). These "lipid rafts" have been proposed to control many membrane processes including apical sorting, protein trafficking, and the clustering of proteins during signaling. The dynamic formation and destruction of lipid nanodomains are thought to provide the central mechanism to regulate this wide range of essential processes (2-4). Although many methods now provide strong evidence to support their existence in vivo (5), the combination of nanoscopic size and dynamics on millisecond timescales has placed the direct observation of their behavior beyond the scope of existing techniques. Consequently, although we know they exist, frustratingly little is known regarding their function and dynamics (6).Recent advances in fluorescence nanoscopy provide the only time-dependent information on the behavior of lipid nanodomains (7-9). Stimulated emission depletion-fluorescence correlation spectroscopy has shown cholesterol-mediated hindered nanoscale diffusion of single labeled sphingomyelin lipids that is consistent with the lipid raft hypothesis and transient binding of lipids (9). Superresolution fluorescence microscopy has also revealed protein clusters in cell membranes with 0.5-s temporal resolution (7). All of these experiments, however, are limited in temporal resolution by fluorescence, and must infer lipid nanodomains from the addition of fluorescent labels.Macroscopic phase separation in artificial lipid bilayers has been widely used to help understand the biological implications of domain formation. Different lipid phases can be visualized using fluorescence microscopy with labels that preferentially partition into a specific phase (10-12). This approach is successful for micrometer-sized domains but inevitably fails on the tens to few hundreds of nanometers scale due to limitations in phase specificity, the limited residence time of a label within a specific nanoscopic domain, and the achievable optical resolution (13). The fluorescent probe is itself an additional component that can perturb phase behavior, either directly or through photooxidation (14, 15). As ...

show abstract

Section: Discussionmentioning

confidence: 95%

Dynamic label-free imaging of lipid nanodomains

Wit

Danial

Kukura

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

100

View full text Add to dashboard Cite

show abstract

“…Analogously to single particle tracking, these experiments provide trajectories from which the time-and ensemble-averaged MSD can be calculated, thus allowing one to test the appearance of nonergodicity. In addition, the technical advantages afforded by dual color tracking make it possible to experimentally verify the occurrence of interactions between diffusing species, measure the duration of such events, and check whether they affect the diffusivity of the particles involved [13,15,16]. These experiments can be carried out by labeling chemically identical components as well as different species, thus testing the formation of both homo-and heterooligomers.…”

Section: Resultsmentioning

confidence: 99%

“…These experiments can be carried out by labeling chemically identical components as well as different species, thus testing the formation of both homo-and heterooligomers. This technique has already been successfully used to study interactions of several membrane components [13,15,16]. In addition, other promising approaches to investigate interaction-dependent diffusion include hyper-spectral microscopy [12], as well as the combination of single particle tracking with recent methods based on advanced statistical tools [10,30] and on the spatiotemporal analysis of fluorescence fluctuations [31], which have been shown to provide a wealth of information into dynamic molecular processes of biological relevance.…”

Section: Resultsmentioning

confidence: 99%

“…From the biophysical point of view, the model reflects the scenario of a diffusing molecule which, upon interaction with another molecule, undergoes a transient change of diffusivity for the time the interaction takes place. An example of this effect is provided by the formation of transient dimers and oligomers among chemically identical molecules [15,16], as well as by interactions occurring among different molecular species. Since these scenarios might include a variety of interactions between a multiplicity of cellular components (such as proteins, lipids, vesicles, or organelles), for the sake of generality we will refer to the random walkers as prey and hunters.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Nonergodic subdiffusion from transient interactions with heterogeneous partners

et al. 2017

View full text Add to dashboard Cite

Spatiotemporal disorder has been recently associated to the occurrence of anomalous nonergodic diffusion of molecular components in biological systems, but the underlying microscopic mechanism is still unclear. We introduce a model in which a particle performs continuous Brownian motion with changes of diffusion coefficients induced by transient molecular interactions with diffusive binding partners. In spite of the exponential distribution of waiting times, the model shows subdiffusion and nonergodicity similar to the heavy-tailed continuous time random walk. The dependence of these properties on the density of binding partners is analyzed and discussed. Our work provides an experimentally-testable microscopic model to investigate the nature of nonergodicity in disordered media.

show abstract

“…L'accumulation de protéines « cargo » peut également se faire selon un processus actif, comme pour les GPI-AP qui sont présentes au niveau des microdomaines lipidiques sous forme de clusters ou de monomères, et qui peuvent être rassemblés sous l'action du cytosquelette d'actine corticale [48]. Il a également été proposé que le cholestérol permette la stabilisation d'homodimères qui ne sont formés que de manière transitoire en son absence [49]. …”

Section: Les Microdomaines Lipidiques à L'origine De L'invagination Eunclassified

Endocytose sans clathrine

Blouin

2013

Med Sci (Paris)

View full text Add to dashboard Cite

Transient GPI-anchored protein homodimers are units for raft organization and function

Cited by 239 publications

References 50 publications

Dynamic label-free imaging of lipid nanodomains

Dynamic label-free imaging of lipid nanodomains

Nonergodic subdiffusion from transient interactions with heterogeneous partners

Endocytose sans clathrine

Contact Info

Product

Resources

About