scholarly journals Formation mechanism of a diffusion barrier in the initial segment membrane of the neuron as studied by single molecule techniques

2001 ◽  
Vol 41 (supplement) ◽  
pp. S28
Author(s):  
C. Nakada ◽  
Kenneth Ritchie ◽  
T. Fujiwara ◽  
Y. Hotta ◽  
R. Iino ◽  
...  
Keyword(s):  
Formation Mechanism ◽  
Single Molecule ◽  
Diffusion Barrier ◽  
Initial Segment

scholarly journals Developmental formation of a diffusion barrier in the axonal initial segment membrane of the neuron ; a single molecule approach.

2001 ◽  
Vol 41 (supplement) ◽  
pp. S121
Author(s):  
C. Nakada ◽  
Kenneth Ritchie ◽  
T. Fujiwara ◽  
Y. Hotta ◽  
R. Iino ◽  
...  
Keyword(s):  
Single Molecule ◽  
Diffusion Barrier ◽  
Initial Segment ◽  
Axonal Initial Segment

scholarly journals LS3A1 Diffusion barrier in the neuronal cell membrane : a single molecule study

2002 ◽  
Vol 42 (supplement2) ◽  
pp. S223
Author(s):  
C. Nakada ◽  
Kenneth Ritchie ◽  
T. Fujiwara ◽  
M. Nakamura ◽  
Y. Oba ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Single Molecule ◽  
Diffusion Barrier ◽  
Neuronal Cell

scholarly journals Developmental formation of a diffusion barrier in the plasma membrane of the axonal initial segment : single lipid molecule approach

2000 ◽  
Vol 40 (supplement) ◽  
pp. S212
Author(s):  
C. Nakada ◽  
M. Nozaki ◽  
H. Yamashita ◽  
K. Yamaguchi ◽  
Ken Ritchie ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Diffusion Barrier ◽  
Initial Segment ◽  
Lipid Molecule ◽  
Axonal Initial Segment

scholarly journals BBSome trains remove activated GPCRs from cilia by enabling passage through the transition zone

2018 ◽  
Vol 217 (5) ◽  
pp. 1847-1868 ◽  
Author(s):  
Fan Ye ◽  
Andrew R. Nager ◽  
Maxence V. Nachury
Keyword(s):  
Transition Zone ◽  
Single Molecule ◽  
Diffusion Barrier ◽  
Diffusion Barriers ◽  
G Protein Coupled Receptors ◽  
Lateral Transport ◽  
Step Process ◽  
Signaling Receptors ◽  
Guanosine Triphosphatase ◽  
G Protein Coupled

A diffusion barrier at the transition zone enables the compartmentalization of signaling molecules by cilia. The BBSome and the small guanosine triphosphatase Arl6, which triggers BBSome coat polymerization, are required for the exit of activated signaling receptors from cilia, but how diffusion barriers are crossed when membrane proteins exit cilia remains to be determined. In this study, we found that activation of the ciliary G protein–coupled receptors (GPCRs) Smoothened and SSTR3 drove the Arl6-dependent assembly of large, highly processive, and cargo-laden retrograde BBSome trains. Single-molecule imaging revealed that the assembly of BBSome trains enables the lateral transport of ciliary GPCRs across the transition zone. However, the removal of activated GPCRs from cilia was inefficient because a second periciliary diffusion barrier was infrequently crossed. We conclude that exit from cilia is a two-step process in which BBSome/Arl6 trains first move activated GPCRs through the transition zone before a periciliary barrier can be crossed.

scholarly journals BBSome trains remove activated GPCRs from cilia by enabling passage through the transition zone

2017 ◽  
Author(s):  
Fan Ye ◽  
Andrew R. Nager ◽  
Maxence V. Nachury
Keyword(s):  
Transition Zone ◽  
Single Molecule ◽  
Diffusion Barrier ◽  
Small Gtpase ◽  
Single Molecule Imaging ◽  
Lateral Transport ◽  
Step Process ◽  
On Demand ◽  
Gpcr Activation ◽  
Signaling Receptors

AbstractA diffusion barrier at the transition zone enables the compartmentalization of signaling molecules by cilia. The BBSome and the small GTPase Arl6, which triggers BBSome coat polymerization, are required for the exit of activated signaling receptors from cilia, but how diffusion barriers are crossed when membrane proteins exit cilia remains to be determined. Here we found that activation of the ciliary GPCRs Smoothened and SSTR3 drove the Arl6-dependent assembly of large, highly processive and cargo-laden retrograde BBSome trains. Single-molecule imaging revealed that the assembly of BBSome trains enables the lateral transport of ciliary GPCRs across the transition zone. Yet, the removal of activated GPCRs from cilia was inefficient because a second, periciliary diffusion barrier was infrequently crossed. We conclude that exit from cilia is a two-step process in which BBSome/Arl6 trains first moves activated GPCRs through the transition zone before a periciliary barrier can be crossed.SummaryUpon activation, GPCRs must exit cilia for appropriate signal transduction. Using bulk imaging of BBSome and single molecule imaging of GPCRs, Ye et al. demonstrate that retrograde BBSome trains assemble on-demand upon GPCR activation and ferry GPCRs across the transition zone. Yet, ciliary exit often fails because of a second diffusion barrier.

scholarly journals Nanoscopic compartmentalization of membrane protein motion at the axon initial segment

2016 ◽  
Author(s):  
David Albrecht ◽  
Christian M. Winterflood ◽  
Thomas Tschager ◽  
Helge Ewers
Keyword(s):  
Membrane Protein ◽  
Particle Tracking ◽  
Single Particle ◽  
Diffusion Barrier ◽  
High Speed ◽  
Initial Segment ◽  
Single Particle Tracking ◽  
Axon Initial Segment ◽  
Periodic Pattern ◽  
Protein Motion

AbstractThe axon initial segment (AIS) is enriched in specific adaptor, cytoskeletal and transmembrane molecules. During AIS establishment, a membrane diffusion barrier is formed between the axon and the somatodendritic domain. Recently, an axonal periodic pattern of actin, spectrin and ankyrin forming 190 nm distanced, ring-like structures has been discovered. However, whether this structure is related to the diffusion barrier function is unclear.Here, we performed single particle tracking timecourse experiments on hippocampal neurons during AIS development. We analyzed the mobility of lipid-anchored molecules by high-speed single particle tracking and correlated positions of membrane molecules with the nanoscopic organization of the AIS cytoskeleton.We observe a strong reduction in mobility early in AIS development. Membrane protein motion in the AIS plasma membrane is confined to a repetitive pattern of ~190 nm spaced segments along the AIS axis as early as DIV4 and this pattern alternates with actin rings. Our data provide a new model for the mechanism of the AIS diffusion barrier.

scholarly journals Nanoscopic compartmentalization of membrane protein motion at the axon initial segment

2016 ◽  
Vol 215 (1) ◽  
pp. 37-46 ◽  
Author(s):  
David Albrecht ◽  
Christian M. Winterflood ◽  
Mohsen Sadeghi ◽  
Thomas Tschager ◽  
Frank Noé ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Particle Tracking ◽  
Single Particle ◽  
Diffusion Barrier ◽  
Initial Segment ◽  
Time Course ◽  
Single Particle Tracking ◽  
Axon Initial Segment ◽  
Periodic Pattern ◽  
Protein Motion

The axon initial segment (AIS) is enriched in specific adaptor, cytoskeletal, and transmembrane molecules. During AIS establishment, a membrane diffusion barrier is formed between the axonal and somatodendritic domains. Recently, an axonal periodic pattern of actin, spectrin, and ankyrin forming 190-nm-spaced, ring-like structures has been discovered. However, whether this structure is related to the diffusion barrier function is unclear. Here, we performed single-particle tracking time-course experiments on hippocampal neurons during AIS development. We analyzed the mobility of lipid-anchored molecules by high-speed single-particle tracking and correlated positions of membrane molecules with the nanoscopic organization of the AIS cytoskeleton. We observe a strong reduction in mobility early in AIS development. Membrane protein motion in the AIS plasma membrane is confined to a repetitive pattern of ∼190-nm-spaced segments along the AIS axis as early as day in vitro 4, and this pattern alternates with actin rings. Mathematical modeling shows that diffusion barriers between the segments significantly reduce lateral diffusion along the axon.

scholarly journals REALM: AO-based localization microscopy deep in complex tissue

2020 ◽  
Author(s):  
Marijn E. Siemons ◽  
Naomi A.K. Hanemaaijer ◽  
Maarten H.P. Kole ◽  
Lukas C. Kapitein
Keyword(s):  
Brain Tissue ◽  
Adaptive Optics ◽  
Single Molecule ◽  
Initial Segment ◽  
Biological Tissues ◽  
Axon Initial Segment ◽  
Localization Microscopy ◽  
Detection And Localization ◽  
Single Molecule Localization Microscopy

AbstractPerforming Single-Molecule Localization Microscopy (SMLM) in complex biological tissues, where sample-induced aberrations hamper detection and localization, has remained a challenge. Here we establish REALM (Robust and Effective Adaptive Optics in Localization Microscopy), which corrects aberrations of ≤1 rad RMS using 297 frames of blinking molecules to improve single-molecule localization. We demonstrate this method by resolving the periodic cytoskeleton of the axon initial segment at 50 μm depth in brain tissue.

scholarly journals Axonal spectrins: All-purpose fences

2013 ◽  
Vol 203 (3) ◽  
pp. 381-383 ◽  
Author(s):  
Yael Eshed-Eisenbach ◽  
Elior Peles
Keyword(s):  
Adhesion Molecules ◽  
Diffusion Barrier ◽  
Initial Segment ◽  
Nodes Of Ranvier ◽  
Myelinated Axons ◽  
Membrane Cytoskeleton ◽  
Cell Biol ◽  
Axonal Initial Segment ◽  
Membrane Barrier

A membrane barrier important for assembly of the nodes of Ranvier is found at the paranodal junction. This junction is comprised of axonal and glial adhesion molecules linked to the axonal actin–spectrin membrane cytoskeleton through specific adaptors. In this issue, Zhang et al. (2013. J. Cell Biol. http://dx.doi.org/10.1083/jcb.201308116) show that axonal βII spectrin maintains the diffusion barrier at the paranodal junction. Thus, βII spectrin serves to compartmentalize the membrane of myelinated axons at specific locations that are determined either intrinsically (i.e., at the axonal initial segment), or by axoglial contacts (i.e., at the paranodal junction).

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