Arl2-GTP and Arl3-GTP regulate a GDI-like transport system for farnesylated cargo

Ismail, Shehab; Chen, Yong-Xiang; Rusinova, Alexandra; Chandra, Anchal; Bierbaum, Martin; Gremer, Lothar; Triola, Gemma; Waldmann, Herbert; Bastiaens, Philippe I. H.; Wittinghofer, Alfred

doi:10.1038/nchembio.686

Cited by 238 publications

(387 citation statements)

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“…Finally, protein chaperones may exist that facilitate removal of prenylated βγ from membranes. Many such proteins are known to act on prenylated small GTPases (20)(21)(22), and phosducin is known to facilitate βγ translocation in photoreceptors by diminishing its membrane partitioning (23,24). It is unknown whether chaperones regulate βγ translocation in other cell types.…”

Section: Same Residues That Determine βγ-Translocation Rates Directlymentioning

confidence: 99%

G-protein signaling leverages subunit-dependent membrane affinity to differentially control βγ translocation to intracellular membranes

O’Neill¹,

Karunarathne²,

Kalyanaraman³

et al. 2012

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

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Activation of G-protein heterotrimers by receptors at the plasma membrane stimulates βγ-complex dissociation from the α-subunit and translocation to internal membranes. This intermembrane movement of lipid-modified proteins is a fundamental but poorly understood feature of cell signaling. The differential translocation of G-protein βγ-subunit types provides a valuable experimental model to examine the movement of signaling proteins between membranes in a living cell. We used live cell imaging, mathematical modeling, and in vitro measurements of lipidated fluorescent peptide dissociation from vesicles to determine the mechanistic basis of the intermembrane movement and identify the interactions responsible for differential translocation kinetics in this family of evolutionarily conserved proteins. We found that the reversible translocation is mediated by the limited affinity of the βγ-subunits for membranes. The differential kinetics of the βγ-subunit types are determined by variations among a set of basic and hydrophobic residues in the γ-subunit types. Gprotein signaling thus leverages the wide variation in membrane dissociation rates among different γ-subunit types to differentially control βγ-translocation kinetics in response to receptor activation. The conservation of primary structures of γ-subunits across mammalian species suggests that there can be evolutionary selection for primary structures that confer specific membrane-binding affinities and consequent rates of intermembrane movement.protein-membrane interaction | spatio-temporal dynamics | G protein-coupled receptors C ompared with the vast biochemical information available for signaling proteins from cell-disruptive techniques, much less is known about their spatiotemporal dynamics in the 3D space of an intact living cell. Many important signaling proteins are posttranslationally modified with lipid groups that facilitate their interactions with membranes. Live cell imaging has so far revealed important roles for constitutive cycles that maintain proper localization of lipidated proteins (1) and for dynamic protein redistribution throughout the cell in response to a signal (2), but the detailed nature of lipid-modified protein movement between membranes is generally not well understood.Heterotrimeric G proteins consist of lipid-modified α-and βγ-subunits (3). They are central transducers of the most important signaling pathways in mammals, yet little is known about their intracellular movement. Inactive heterotrimers consist of a GDP-bound α-subunit in complex with a stable βγ-dimer and localize to the plasma membrane (3). Extracellular signals activate transmembrane G-protein-coupled receptors (GPCRs) that catalyze nucleotide exchange on the G-protein α-subunit (3). The βγ-complex can then dissociate from the active α-subunit and translocate from the plasma membrane to intracellular membranes (4-6). βγ translocation has been observed for many different cell types and receptor types, suggesting that it is a common feature of G-protein signaling (4-...

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Section: Same Residues That Determine βγ-Translocation Rates Directlymentioning

confidence: 99%

G-protein signaling leverages subunit-dependent membrane affinity to differentially control βγ translocation to intracellular membranes

O’Neill¹,

Karunarathne²,

Kalyanaraman³

et al. 2012

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

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“…The structures showed how the binding of Arl2 (or Arl3) induces the hydrophobic pocket to narrow such that the C-terminal farnesylated end of the protein gets squeezed out of the pocket. 41 A structure of PDE6d and a geranylgeranylated peptide (with 4 isoprenyl groups rather than 3 compared to farnesylated peptides) from the a' subunit of PDE6 could also be solved. It shows that the C20 modification can bind into the same pocket such that the extra 5 residues of the geranylgeranyl group extend the pocket by 5 C atoms.…”

Section: The Similarity Between Arl2 and Arl3mentioning

confidence: 99%

“…Based on studies with Ras or Rheb, 2 prenylated proteins that reside in cytoplasmic membranes, it was assumed that the nature of cargo does not influence the interaction with PDE6d. 41 It was also shown that the affinity is dictated by only the last few C-terminal residues of these proteins, since C-terminal peptides of 6-7 residues bind with the same affinity as the full-length protein. 34 However, investigation of the interaction of the ciliary protein inositol 5 0 phosphatase (INPP5E) with PDE6d revealed a difference in the binding affinity when compared to the non-ciliary proteins Ras and Rheb.…”

Section: The Similarity Between Arl2 and Arl3mentioning

confidence: 99%

“…[33][34][35][36][37][38][39] In contrast to RhoGDI and RabGDI which are specific for the GDP-bound conformation of prenylated Rho or Rab proteins, 39,40 PDE6d binds Ras and Rheb independent of their nucleotidebound conformation. 34,41 The structure of the Arl2-PDE6d complex shows however that the hydrophobic pocket is partially occupied suggesting a mutually exclusive binding to prenylated cargo and/or Arl2. Biochemical studies with farnesylated peptides showed that both Arl2 and Arl3 in the GTP-bound conformation can allosterically release Ras or Rheb from PDE6d 41 and that Arl2/3 or cargo binding are indeed mutually exclusive.…”

Section: The Similarity Between Arl2 and Arl3mentioning

confidence: 99%

“…34,41 The structure of the Arl2-PDE6d complex shows however that the hydrophobic pocket is partially occupied suggesting a mutually exclusive binding to prenylated cargo and/or Arl2. Biochemical studies with farnesylated peptides showed that both Arl2 and Arl3 in the GTP-bound conformation can allosterically release Ras or Rheb from PDE6d 41 and that Arl2/3 or cargo binding are indeed mutually exclusive.…”

Section: The Similarity Between Arl2 and Arl3mentioning

confidence: 99%

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