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Cholesterol sensor ORP1L contacts the ER protein VAP to control Rab7-RILP-p150 Glued and late endosome positioning.

Rocha N, Kuijl C, van der Kant R, Janssen L, Houben D, Janssen H, Zwart W, Neefjes J - J. Cell Biol. (2009)

Bottom Line: Motor proteins associated to the dynactin subunit p150(Glued) bind to LEs via the Rab7 effector Rab7-interacting lysosomal protein (RILP) in association with the oxysterol-binding protein ORP1L.At these sites, the ER protein VAP (VAMP [vesicle-associated membrane protein]-associated ER protein) can interact in trans with the Rab7-RILP complex to remove p150(Glued) and associated motors.Under high cholesterol conditions, as in Niemann-Pick type C disease, this process is prevented, and LEs accumulate at the microtubule minus end as the result of dynein motor activity.

View Article: PubMed Central - PubMed

Affiliation: Division of Cell Biology, The Netherlands Cancer Institute, 1066CX Amsterdam, Netherlands.

ABSTRACT
Late endosomes (LEs) have characteristic intracellular distributions determined by their interactions with various motor proteins. Motor proteins associated to the dynactin subunit p150(Glued) bind to LEs via the Rab7 effector Rab7-interacting lysosomal protein (RILP) in association with the oxysterol-binding protein ORP1L. We found that cholesterol levels in LEs are sensed by ORP1L and are lower in peripheral vesicles. Under low cholesterol conditions, ORP1L conformation induces the formation of endoplasmic reticulum (ER)-LE membrane contact sites. At these sites, the ER protein VAP (VAMP [vesicle-associated membrane protein]-associated ER protein) can interact in trans with the Rab7-RILP complex to remove p150(Glued) and associated motors. LEs then move to the microtubule plus end. Under high cholesterol conditions, as in Niemann-Pick type C disease, this process is prevented, and LEs accumulate at the microtubule minus end as the result of dynein motor activity. These data explain how the ER and cholesterol control the association of LEs with motor proteins and their positioning in cells.

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Model showing control of Rab7–RILP–p150Glued motor protein complexes by the ER protein VAP, cholesterol, and the sensor ORP1L. Rab7 recruits the homodimeric effector protein RILP to LEs. RILP binds the p150Glued subunit of the dynein–dynactin motor. ORP1L also binds to the Rab7–RILP complex. ORP1L has a C-terminal cholesterol-sensing ORD that exists in different conformational states determined by cholesterol in LEs. At low cholesterol levels, ORD adopts a conformation in which the adjacent FFAT motif is exposed and which can be detected by the ER protein VAP in ER–LE MCSs. VAP binds in trans to the Rab7–RILP–p150Glued complex and removes p150Glued, thus preventing minus end–directed transport. High cholesterol conditions initiate a different ORP1L conformation, preventing formation of ER–LE MCSs, and VAP fails to interact with the Rab7–RILP–p150Glued complex. Thus, cholesterol levels in LEs determine the conformation of ORP1L and thereby VAP recruitment in ER–LE contact sites. The ER protein VAP then controls p150Glued binding to Rab7–RILP, resulting in the scattering of cholesterol-poor LEs and clustering of cholesterol-laden LEs, as in Niemann-Pick type C disease.
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fig9: Model showing control of Rab7–RILP–p150Glued motor protein complexes by the ER protein VAP, cholesterol, and the sensor ORP1L. Rab7 recruits the homodimeric effector protein RILP to LEs. RILP binds the p150Glued subunit of the dynein–dynactin motor. ORP1L also binds to the Rab7–RILP complex. ORP1L has a C-terminal cholesterol-sensing ORD that exists in different conformational states determined by cholesterol in LEs. At low cholesterol levels, ORD adopts a conformation in which the adjacent FFAT motif is exposed and which can be detected by the ER protein VAP in ER–LE MCSs. VAP binds in trans to the Rab7–RILP–p150Glued complex and removes p150Glued, thus preventing minus end–directed transport. High cholesterol conditions initiate a different ORP1L conformation, preventing formation of ER–LE MCSs, and VAP fails to interact with the Rab7–RILP–p150Glued complex. Thus, cholesterol levels in LEs determine the conformation of ORP1L and thereby VAP recruitment in ER–LE contact sites. The ER protein VAP then controls p150Glued binding to Rab7–RILP, resulting in the scattering of cholesterol-poor LEs and clustering of cholesterol-laden LEs, as in Niemann-Pick type C disease.

Mentions: We have visualized how the Rab7–RILP complex controls intracellular positioning of LEs. This process is controlled by cholesterol levels sensed by ORP1L to induce ER–LE contact sites via interaction with the ER protein VAP. In these contact sites, VAP interacts in trans with the Rab7–RILP receptor, promoting dissociation of p150Glued and its associated motor proteins (Fig. 9). This model explains how cholesterol depletion causes LE scattering and high cholesterol levels induce LE clustering, as observed in Niemann-Pick type C disease. We reveal an unexpected contribution of ER proteins in the control of LE intracellular positioning by motor proteins in a process controlled by cholesterol.


Cholesterol sensor ORP1L contacts the ER protein VAP to control Rab7-RILP-p150 Glued and late endosome positioning.

Rocha N, Kuijl C, van der Kant R, Janssen L, Houben D, Janssen H, Zwart W, Neefjes J - J. Cell Biol. (2009)

Model showing control of Rab7–RILP–p150Glued motor protein complexes by the ER protein VAP, cholesterol, and the sensor ORP1L. Rab7 recruits the homodimeric effector protein RILP to LEs. RILP binds the p150Glued subunit of the dynein–dynactin motor. ORP1L also binds to the Rab7–RILP complex. ORP1L has a C-terminal cholesterol-sensing ORD that exists in different conformational states determined by cholesterol in LEs. At low cholesterol levels, ORD adopts a conformation in which the adjacent FFAT motif is exposed and which can be detected by the ER protein VAP in ER–LE MCSs. VAP binds in trans to the Rab7–RILP–p150Glued complex and removes p150Glued, thus preventing minus end–directed transport. High cholesterol conditions initiate a different ORP1L conformation, preventing formation of ER–LE MCSs, and VAP fails to interact with the Rab7–RILP–p150Glued complex. Thus, cholesterol levels in LEs determine the conformation of ORP1L and thereby VAP recruitment in ER–LE contact sites. The ER protein VAP then controls p150Glued binding to Rab7–RILP, resulting in the scattering of cholesterol-poor LEs and clustering of cholesterol-laden LEs, as in Niemann-Pick type C disease.
© Copyright Policy - openaccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2712958&req=5

fig9: Model showing control of Rab7–RILP–p150Glued motor protein complexes by the ER protein VAP, cholesterol, and the sensor ORP1L. Rab7 recruits the homodimeric effector protein RILP to LEs. RILP binds the p150Glued subunit of the dynein–dynactin motor. ORP1L also binds to the Rab7–RILP complex. ORP1L has a C-terminal cholesterol-sensing ORD that exists in different conformational states determined by cholesterol in LEs. At low cholesterol levels, ORD adopts a conformation in which the adjacent FFAT motif is exposed and which can be detected by the ER protein VAP in ER–LE MCSs. VAP binds in trans to the Rab7–RILP–p150Glued complex and removes p150Glued, thus preventing minus end–directed transport. High cholesterol conditions initiate a different ORP1L conformation, preventing formation of ER–LE MCSs, and VAP fails to interact with the Rab7–RILP–p150Glued complex. Thus, cholesterol levels in LEs determine the conformation of ORP1L and thereby VAP recruitment in ER–LE contact sites. The ER protein VAP then controls p150Glued binding to Rab7–RILP, resulting in the scattering of cholesterol-poor LEs and clustering of cholesterol-laden LEs, as in Niemann-Pick type C disease.
Mentions: We have visualized how the Rab7–RILP complex controls intracellular positioning of LEs. This process is controlled by cholesterol levels sensed by ORP1L to induce ER–LE contact sites via interaction with the ER protein VAP. In these contact sites, VAP interacts in trans with the Rab7–RILP receptor, promoting dissociation of p150Glued and its associated motor proteins (Fig. 9). This model explains how cholesterol depletion causes LE scattering and high cholesterol levels induce LE clustering, as observed in Niemann-Pick type C disease. We reveal an unexpected contribution of ER proteins in the control of LE intracellular positioning by motor proteins in a process controlled by cholesterol.

Bottom Line: Motor proteins associated to the dynactin subunit p150(Glued) bind to LEs via the Rab7 effector Rab7-interacting lysosomal protein (RILP) in association with the oxysterol-binding protein ORP1L.At these sites, the ER protein VAP (VAMP [vesicle-associated membrane protein]-associated ER protein) can interact in trans with the Rab7-RILP complex to remove p150(Glued) and associated motors.Under high cholesterol conditions, as in Niemann-Pick type C disease, this process is prevented, and LEs accumulate at the microtubule minus end as the result of dynein motor activity.

View Article: PubMed Central - PubMed

Affiliation: Division of Cell Biology, The Netherlands Cancer Institute, 1066CX Amsterdam, Netherlands.

ABSTRACT
Late endosomes (LEs) have characteristic intracellular distributions determined by their interactions with various motor proteins. Motor proteins associated to the dynactin subunit p150(Glued) bind to LEs via the Rab7 effector Rab7-interacting lysosomal protein (RILP) in association with the oxysterol-binding protein ORP1L. We found that cholesterol levels in LEs are sensed by ORP1L and are lower in peripheral vesicles. Under low cholesterol conditions, ORP1L conformation induces the formation of endoplasmic reticulum (ER)-LE membrane contact sites. At these sites, the ER protein VAP (VAMP [vesicle-associated membrane protein]-associated ER protein) can interact in trans with the Rab7-RILP complex to remove p150(Glued) and associated motors. LEs then move to the microtubule plus end. Under high cholesterol conditions, as in Niemann-Pick type C disease, this process is prevented, and LEs accumulate at the microtubule minus end as the result of dynein motor activity. These data explain how the ER and cholesterol control the association of LEs with motor proteins and their positioning in cells.

Show MeSH
Related in: MedlinePlus