RhoGTPase-binding proteins, the exocyst complex and polarized vesicle trafficking

Mukherjee, Debarati; Sen, Aditi; Aguilar, R. Claudio

doi:10.4161/sgtp.28453

Cited by 22 publications

(14 citation statements)

References 79 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Well-defined cellular roles in yeast include localization of the exocyst to sites of active secretion in yeast budding (TerBush et al, 1996) and in animal systems include neurite outgrowth (Vega and Hsu, 2001) and regulated trafficking of the Glucose transporter type4 (GLUT4) in adipocytes (Inoue et al, 2003). In these various systems, the exocyst function is in turn regulated by members of the Ras homolous (Rho), Raslike (Ral), and Ras-related in brain (Rab) families of small Guanosinetriphosphatases (GTPases; for review, see Mukherjee et al, 2014). Following a compatible pollination on the Brassicaceae dry stigma, unknown factors are proposed to be released towards the pollen grain, and this is likely accomplished by the exocyst functioning in its conserved role as a multisubunit tethering complex to dock secretory vesicles under the pollen attachment site (see model in Fig.…”

Section: Discussionmentioning

confidence: 99%

RNA silencing of exocyst genes in the stigma impairs the acceptance of compatible pollen in Arabidopsis

et al. 2015

View full text Add to dashboard Cite

Initial pollen-pistil interactions in the Brassicaceae are regulated by rapid communication between pollen grains and stigmatic papillae and are fundamentally important, as they are the first step toward successful fertilization. The goal of this study was to examine the requirement of exocyst subunits, which function in docking secretory vesicles to sites of polarized secretion, in the context of pollen-pistil interactions. One of the exocyst subunit genes, EXO70A1, was previously identified as an essential factor in the stigma for the acceptance of compatible pollen in Arabidopsis (Arabidopsis thaliana) and Brassica napus. We hypothesized that EXO70A1, along with other exocyst subunits, functions in the Brassicaceae dry stigma to deliver cargo-bearing secretory vesicles to the stigmatic papillar plasma membrane, under the pollen attachment site, for pollen hydration and pollen tube entry. Here, we investigated the functions of exocyst complex genes encoding the remaining seven subunits, SECRETORY3 (SEC3), SEC5, SEC6, SEC8, SEC10, SEC15, and EXO84, in Arabidopsis stigmas following compatible pollinations. Stigma-specific RNAsilencing constructs were used to suppress the expression of each exocyst subunit individually. The early postpollination stages of pollen grain adhesion, pollen hydration, pollen tube penetration, seed set, and overall fertility were analyzed in the transgenic lines to evaluate the requirement of each exocyst subunit. Our findings provide comprehensive evidence that all eight exocyst subunits are necessary in the stigma for the acceptance of compatible pollen. Thus, this work implicates a fully functional exocyst complex as a component of the compatible pollen response pathway to promote pollen acceptance.

show abstract

Section: Discussionmentioning

confidence: 99%

RNA silencing of exocyst genes in the stigma impairs the acceptance of compatible pollen in Arabidopsis

et al. 2015

View full text Add to dashboard Cite

show abstract

“…This review aims to summarize some of them, and to further highlight the importance of the exocyst complex in normal cell function and pathological situations. The interplay between the exocyst and its regulators have been extensively reviewed elsewhere (e.g., Wu et al, 2008 ; Guichard et al, 2014 ; Mukherjee et al, 2014 ; Shirakawa and Horiuchi, 2015 ) and are not emphasized here.…”

Section: Introductionmentioning

confidence: 99%

The Exocyst Complex in Health and Disease

Martín-Urdiroz

Deeks

Horton

et al. 2016

Front. Cell Dev. Biol.

103

View full text Add to dashboard Cite

Exocytosis involves the fusion of intracellular secretory vesicles with the plasma membrane, thereby delivering integral membrane proteins to the cell surface and releasing material into the extracellular space. Importantly, exocytosis also provides a source of lipid moieties for membrane extension. The tethering of the secretory vesicle before docking and fusion with the plasma membrane is mediated by the exocyst complex, an evolutionary conserved octameric complex of proteins. Recent findings indicate that the exocyst complex also takes part in other intra-cellular processes besides secretion. These various functions seem to converge toward defining a direction of membrane growth in a range of systems from fungi to plants and from neurons to cilia. In this review we summarize the current knowledge of exocyst function in cell polarity, signaling and cell-cell communication and discuss implications for plant and animal health and disease.

show abstract

“…Secretory vesicles generated from the trans-Golgi network carrying newly synthesized cargos or from endosomal compartments often carrying recycled cargos are transported to specific areas of the cell, leading to cell polarization. The evolutionarily conserved exocyst, an octameric protein complex, plays an important role in polarized exocytosis during many cellular activities including cell migration and epithelial polarization (He and Guo, 2009; Mukherjee et al, 2014; Orlando and Guo, 2009), including the control of directional vesicle trafficking to leading edges in migrating cells (Fletcher and Rappoport, 2010; He and Guo, 2009; Ulrich and Heisenberg, 2009). One of the components of the exocyst is the RAB small GTPases.…”

Section: Introductionmentioning

confidence: 99%

PKN1 Directs Polarized RAB21 Vesicle Trafficking via RPH3A and Is Important for Neutrophil Adhesion and Ischemia-Reperfusion Injury

Yuan

Ren

et al. 2017

Cell Reports

View full text Add to dashboard Cite

SUMMARY Polarized vesicle transport plays an important role in cell polarization, but the mechanisms underlying this process and its role in innate immune responses are not well understood. Here, we describe a phosphorylation-regulated polarization mechanism that is important for neutrophil adhesion to endothelial cells during inflammatory responses. We show that the protein kinase PKN1 phosphorylates RPH3A, which enhances binding of RPH3A to GTP-bound RAB21. These interactions are important for polarized localization of RAB21 and RPH3A in neutrophils, which leads to PIP5K1C90 polarization. Consistent with the roles of PIP5K1C90 polarization, the lack of PKN1 or RPH3A impairs neutrophil integrin activation, adhesion to endothelial cells, and infiltration in inflammatory models. Furthermore, myeloid-specific loss of PKN1 decreases tissue injury in a renal ischemia-reperfusion model. Thus, this study characterizes a mechanism for protein polarization in neutrophils and identifies a potential protein kinase target for therapeutic intervention in reperfusion-related tissue injury.

show abstract

RhoGTPase-binding proteins, the exocyst complex and polarized vesicle trafficking

Cited by 22 publications

References 79 publications

RNA silencing of exocyst genes in the stigma impairs the acceptance of compatible pollen in Arabidopsis

RNA silencing of exocyst genes in the stigma impairs the acceptance of compatible pollen in Arabidopsis

The Exocyst Complex in Health and Disease

PKN1 Directs Polarized RAB21 Vesicle Trafficking via RPH3A and Is Important for Neutrophil Adhesion and Ischemia-Reperfusion Injury

Contact Info

Product

Resources

About