Targeting Rab GTPases to distinct membrane compartments

2004 ◽  
Vol 5 (11) ◽  
pp. 886-896 ◽  
Author(s):  
Suzanne Pfeffer ◽  
Dikran Aivazian
2006 ◽  
Vol 173 (6) ◽  
pp. 917-926 ◽  
Author(s):  
Dikran Aivazian ◽  
Ramon L. Serrano ◽  
Suzanne Pfeffer

The human genome encodes ∼70 Rab GTPases that localize to the surfaces of distinct membrane compartments. To investigate the mechanism of Rab localization, chimeras containing heterologous Rab hypervariable domains were generated, and their ability to bind seven Rab effectors was quantified. Two chimeras could bind effectors for two distinctly localized Rabs; a Rab5/9 hybrid bound both Rab5 and Rab9 effectors, and a Rab1/9 hybrid bound to certain Rab1 and Rab9 effectors. These unusual chimeras permitted a test of the importance of effector binding for Rab localization. In both cases, changing the cellular concentration of a key Rab9 effector, which is called tail-interacting protein of 47 kD, moved a fraction of the proteins from their parental Rab localization to that of Rab9. Thus, relative concentrations of certain competing effectors could determine a chimera's localization. These data confirm the importance of effector interactions for Rab9 localization, and support a model in which effector proteins rely on Rabs as much as Rabs rely on effectors to achieve their correct steady state localizations.


2019 ◽  
Vol 218 (12) ◽  
pp. 4157-4170 ◽  
Author(s):  
Rachel C. Gomez ◽  
Paulina Wawro ◽  
Pawel Lis ◽  
Dario R. Alessi ◽  
Suzanne R. Pfeffer

LRRK2 kinase mutations cause familial Parkinson’s disease and increased phosphorylation of a subset of Rab GTPases. Rab29 recruits LRRK2 to the trans-Golgi and activates it there, yet some of LRRK2’s major Rab substrates are not on the Golgi. We sought to characterize the cell biology of LRRK2 activation. Unlike other Rab family members, we show that Rab29 binds nucleotide weakly, is poorly prenylated, and is not bound to GDI in the cytosol; nevertheless, Rab29 only activates LRRK2 when it is membrane bound and GTP bound. Mitochondrially anchored, GTP-bound Rab29 is both a LRRK2 substrate and activator, and it drives accumulation of active LRRK2 and phosphorylated Rab10 on mitochondria. Importantly, mitochondrially anchored LRRK2 is much less capable of phosphorylating plasma membrane–anchored Rab10 than soluble LRRK2. These data support a model in which LRRK2 associates with and dissociates from distinct membrane compartments to phosphorylate Rab substrates; if anchored, LRRK2 can modify misdelivered Rab substrates that then become trapped there because GDI cannot retrieve them.


2005 ◽  
Vol 33 (4) ◽  
pp. 627-630 ◽  
Author(s):  
S. Pfeffer

The human genome encodes almost 70 Rab GTPases. These proteins are C-terminally geranylgeranylated and are localized to the surfaces of distinct membrane-bound compartments in eukaryotic cells. This mini review presents a working model for how Rabs achieve and maintain their steady-state localizations. Data from a number of laboratories suggest that Rabs participate in the generation of macromolecular assemblies that generate functional microdomains within a given membrane compartment. Our data suggest that these complex interactions are important for the cellular localization of Rab proteins at steady state.


2008 ◽  
Vol 22 (S1) ◽  
Author(s):  
Faiyaz Ahmad Khan ◽  
Rebecka Lindh ◽  
Yan Tang ◽  
Lida Ruishalme ◽  
Anita Ost ◽  
...  

2020 ◽  
Vol 19 (5) ◽  
pp. 900-912 ◽  
Author(s):  
Tatjana Reuter ◽  
Stephanie Vorwerk ◽  
Viktoria Liss ◽  
Tzu-Chiao Chao ◽  
Michael Hensel ◽  
...  

Systemic infection and proliferation of intracellular pathogens require the biogenesis of a growth-stimulating compartment. The gastrointestinal pathogen Salmonella enterica commonly forms highly dynamic and extensive tubular membrane compartments built from Salmonella-modified membranes (SMMs) in diverse host cells. Although the general mechanism involved in the formation of replication-permissive compartments of S. enterica is well researched, much less is known regarding specific adaptations to different host cell types. Using an affinity-based proteome approach, we explored the composition of SMMs in murine macrophages. The systematic characterization provides a broader landscape of host players to the maturation of Salmonella-containing compartments and reveals core host elements targeted by Salmonella in macrophages as well as epithelial cells. However, we also identified subtle host specific adaptations. Some of these observations, such as the differential involvement of the COPII system, Rab GTPases 2A, 8B, 11 and ER transport proteins Sec61 and Sec22B may explain cell line-dependent variations in the pathophysiology of Salmonella infections. In summary, our system-wide approach demonstrates a hitherto underappreciated impact of the host cell type in the formation of intracellular compartments by Salmonella.


1996 ◽  
Vol 270 (5) ◽  
pp. C1263-C1270 ◽  
Author(s):  
K. A. Beck ◽  
W. J. Nelson

Normal cell function is dependent on the existence of membrane compartments that have unique populations of membrane proteins. Sorting of membrane proteins forms the basis for the biogenesis of distinct membrane compartments. There are many examples of membrane protein-sorting events in cells, but the molecular machinery involved is poorly understood. We discuss characteristics of a putative membrane protein-sorting machine and show that the spectrin-based membrane skeleton conforms to these characteristics. The spectrin-based membrane skeleton is a submembranous, spatially limited, two-dimensional lattice that binds a subset of membrane proteins. These properties allow the membrane skeleton to facilitate the formation of distinct membrane domains and thus reveal its potential as a membrane protein-sorting machine.


2000 ◽  
Vol 276 (9) ◽  
pp. 6225-6233 ◽  
Author(s):  
Mohammad Abdul-Ghani ◽  
Pierre-Yves Gougeon ◽  
Derek C. Prosser ◽  
Lance F. Da-Silva ◽  
Johnny K. Ngsee

2003 ◽  
Vol 3 ◽  
pp. 870-880 ◽  
Author(s):  
Rytis Prekeris

Rab GTPases, proteins belonging to the Ras-like small GTP-binding protein superfamily, have emerged as master regulators of cellular membrane transport. Rab11 GTPase, a member of the Rab protein family, plays a role in regulating various cellular functions, including plasma membrane recycling, phagocytosis, and cytokinesis. Rab11 acts by forming mutually exclusive complexes with Rab11-family binding proteins, known as FIPs. Rab11-FIP complexes serve a role of �targeting complexes� by recruiting various membrane traffic factors to cellular membranes. Recent studies have identified several Rab11-FIP complex-binding proteins that regulate distinct membrane traffic pathways.


1998 ◽  
Vol 273 (17) ◽  
pp. 10317-10324 ◽  
Author(s):  
Raj J. Advani ◽  
Hae-Rahn Bae ◽  
Jason B. Bock ◽  
Daniel S. Chao ◽  
Yee-Cheen Doung ◽  
...  

Author(s):  
Peter K. Hepler ◽  
Dale A. Callaham

Calcium ions (Ca) participate in many signal transduction processes, and for that reason it is important to determine where these ions are located within the living cell, and when and to what extent they change their local concentration. Of the different Ca-specific indicators, the fluorescent dyes, developed by Grynkiewicz et al. (1), have proved most efficacious, however, their use on plants has met with several problems (2). First, the dyes as acetoxy-methyl esters are often cleaved by extracellular esterases in the plant cell wall, and thus they do not enter the cell. Second, if the dye crosses the plasma membrane it may continue into non-cytoplasmic membrane compartments. Third, even if cleaved by esterases in the cytoplasm, or introduced as the free acid into the cytoplasmic compartment, the dyes often become quickly sequestered into vacuoles and organelles, or extruded from the cell. Finally, the free acid form of the dye readily complexes with proteins reducing its ability to detect free calcium. All these problems lead to an erroneous measurement of calcium (2).


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