scholarly journals The EFA6 Family: Guanine Nucleotide Exchange Factors for ADP Ribosylation Factor 6 at Neuronal Synapses

2008 ◽  
Vol 214 (3) ◽  
pp. 191-198 ◽  
Author(s):  
Hiroyuki Sakagami
Keyword(s):  
Guanine Nucleotide Exchange Factors ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Adp Ribosylation ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors ◽  
Neuronal Synapses ◽  
Adp Ribosylation Factor

scholarly journals Coordination of Grp1 recruitment mechanisms by its phosphorylation

2020 ◽  
Vol 31 (25) ◽  
pp. 2816-2825
Author(s):  
Jian Li ◽  
David G. Lambright ◽  
Victor W. Hsu
Keyword(s):  
Intracellular Transport ◽  
Small Gtpases ◽  
Guanine Nucleotide Exchange Factors ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Transport Pathways ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors ◽  
Membrane Compartments ◽  
Adp Ribosylation Factor

Intracellular transport pathways are initiated by the recruitment of guanine nucleotide exchange factors (GEFs) that act on the ADP-Ribosylation Factor (ARF) family of small GTPases to membrane compartments. We have elucidated the complexity of recruitment mechanisms that need to be coordinated in localizing an ARF GEF for this process.

scholarly journals Redundant Roles of BIG2 and BIG1, Guanine-Nucleotide Exchange Factors for ADP-Ribosylation Factors in Membrane Traffic between the trans-Golgi Network and Endosomes

2008 ◽  
Vol 19 (6) ◽  
pp. 2650-2660 ◽  
Author(s):  
Ray Ishizaki ◽  
Hye-Won Shin ◽  
Hiroko Mitsuhashi ◽  
Kazuhisa Nakayama
Keyword(s):  
Membrane Traffic ◽  
Guanine Nucleotide Exchange Factors ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Recycling Endosomes ◽  
Adp Ribosylation ◽  
Trans Golgi Network ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors ◽  
Golgi Network

BIG2 and BIG1 are closely related guanine-nucleotide exchange factors (GEFs) for ADP-ribosylation factors (ARFs) and are involved in the regulation of membrane traffic through activating ARFs and recruiting coat protein complexes, such as the COPI complex and the AP-1 clathrin adaptor complex. Although both ARF-GEFs are associated mainly with the trans-Golgi network (TGN) and BIG2 is also associated with recycling endosomes, it is unclear whether BIG2 and BIG1 share some roles in membrane traffic. We here show that knockdown of both BIG2 and BIG1 by RNAi causes mislocalization of a subset of proteins associated with the TGN and recycling endosomes and blocks retrograde transport of furin from late endosomes to the TGN. Similar mislocalization and protein transport block, including furin, were observed in cells depleted of AP-1. Taken together with previous reports, these observations indicate that BIG2 and BIG1 play redundant roles in trafficking between the TGN and endosomes that involves the AP-1 complex.

scholarly journals Localization of Large ADP-Ribosylation Factor-Guanine Nucleotide Exchange Factors to Different Golgi Compartments: Evidence for Distinct Functions in Protein Traffic

2002 ◽  
Vol 13 (1) ◽  
pp. 119-133 ◽  
Author(s):  
Xinhua Zhao ◽  
Troy K.R. Lasell ◽  
Paul Melancİon
Keyword(s):  
Golgi Complex ◽  
Brefeldin A ◽  
Guanine Nucleotide Exchange Factors ◽  
Dependent Manner ◽  
Coat Proteins ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Adp Ribosylation ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors

Activation of several ADP-ribosylation factors (ARFs) by guanine nucleotide exchange factors (GEFs) regulates recruitment of coat proteins (COPs) on the Golgi complex and is generally assumed to be the target of brefeldin A (BFA). The large ARF-GEFs Golgi-specific BFA resistance factor 1 (GBF1) and BFA-inhibited GEFs (BIGs) localize to this organelle but catalyze exchange preferentially on class II and class I ARFs, respectively. We now demonstrate using quantitative confocal microscopy that these GEFs show a very limited overlap with each other (15 and 23%). In contrast, GBF1 colocalizes with the cis-marker p115 (86%), whereas BIGs overlap extensively with TGN38 (83%). Consistent with these distributions, GBF1, but not BIG1, partially relocalized to peripheral sites after incubation at 15°C. The new GBF1 structures represent peripheral vesicular tubular clusters (VTCs) because 88% of structures analyzed stained for both GBF1 and p115. Furthermore, as expected of VTCs, they rapidly reclustered to the Golgi complex in a microtubule-dependent manner upon warm-up. These observations suggest that GBF1 and BIGs activate distinct subclasses of ARFs in specific locations to regulate different types of reactions. In agreement with this possibility, COPI overlapped to a greater extent with GBF1 (64%) than BIG1 (31%), whereas clathrin showed limited overlap with BIG1, and virtually none with GBF1.

scholarly journals ADP-Ribosylation Factor/COPI-dependent Events at the Endoplasmic Reticulum-Golgi Interface Are Regulated by the Guanine Nucleotide Exchange Factor GBF1

2003 ◽  
Vol 14 (6) ◽  
pp. 2250-2261 ◽  
Author(s):  
Rafael García-Mata ◽  
Tomasz Szul ◽  
Cecilia Alvarez ◽  
Elizabeth Sztul
Keyword(s):  
Endoplasmic Reticulum ◽  
Brefeldin A ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Adp Ribosylation ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors ◽  
Nucleotide Exchange Factor ◽  
Two Stages ◽  
Adp Ribosylation Factor

ADP-ribosylation factor (ARF) mediated recruitment of COPI to membranes plays a central role in transport between the endoplasmic reticulum (ER) and the Golgi. The activation of ARFs is mediated by guanine nucleotide exchange factors (GEFs). Although several ARF-GEFs have been identified, the transport steps in which they function are still poorly understood. Here we report that GBF1, a member of the Sec7-domain family of GEFs, is responsible for the regulation of COPI-mediated events at the ER-Golgi interface. We show that GBF1 is essential for the formation, differentiation, and translocation of pre-Golgi intermediates and for the maintenance of Golgi integrity. We also show that the formation of transport-competent ER-to-Golgi intermediates proceeds in two stages: first, a COPI-independent event leads to the formation of an unstable compartment, which is rapidly reabsorbed in the absence of GBF1 activity. Second, the association of GBF1 with this compartment allows COPI recruitment and leads to its maturation into transport intermediates. The recruitment of GBF1 to this compartment is specifically inhibited by brefeldin A. Our findings imply that the continuous recruitment of GBF1 to spatially differentiated membrane domains is required for sustained membrane remodeling that underlies membrane traffic and Golgi biogenesis.

scholarly journals Involvement of the Switch 2 Domain of Ras in Its Interaction with Guanine Nucleotide Exchange Factors

1996 ◽  
Vol 271 (19) ◽  
pp. 11076-11082 ◽  
Author(s):  
Lawrence A. Quilliam ◽  
Mark M. Hisaka ◽  
Sheng Zhong ◽  
Amy Lowry ◽  
Raymond D. Mosteller ◽  
...  
Keyword(s):  
Guanine Nucleotide Exchange Factors ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factors
Sign in / Sign up

Export Citation Format

Share Document