Light microscopy of the endoplasmic reticulum–membrane contact sites in plants

Zang, Jingze; Zhang, T.; Hussey, Patrick J.; Wang, Pengwei

doi:10.1111/jmi.12934

Cited by 10 publications

(5 citation statements)

References 66 publications

(107 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, NET2A is expressed specifically in pollen and forms a complex with the transmembrane POLLEN RECEPTOR-LIKE KINASES (PRK) 4 and 5, indicating that NET proteins could link external signalling events with actin-membrane dynamics 5 . NET3C exists in complexes with VAP27, KINESIN-LIGHT-CHAIN-RELATED (KLCR) and calmodulin-binding IQ67 DOMAIN (IQD) proteins, which mediate the interaction between actin, microtubules and ER at the EPCS 7 , 8 . It is thus possible that EPCS represent focal points of signal sensing and cytoskeletal organization.…”

Section: Introductionmentioning

confidence: 99%

NET4 and RabG3 link actin to the tonoplast and facilitate cytoskeletal remodelling during stomatal immunity

Hawkins,

Kopischke,

Duckney

et al. 2023

Nat Commun

View full text Add to dashboard Cite

Members of the NETWORKED (NET) family are involved in actin-membrane interactions. Here we show that two members of the NET family, NET4A and NET4B, are essential for normal guard cell actin reorganization, which is a process critical for stomatal closure in plant immunity. NET4 proteins interact with F-actin and with members of the Rab7 GTPase RABG3 family through two distinct domains, allowing for simultaneous localization to actin filaments and the tonoplast. NET4 proteins interact with GTP-bound, active RABG3 members, suggesting their function being downstream effectors. We also show that RABG3b is critical for stomatal closure induced by microbial patterns. Taken together, we conclude that the actin cytoskeletal remodelling during stomatal closure involves a molecular link between actin filaments and the tonoplast, which is mediated by the NET4-RABG3b interaction. We propose that stomatal closure to microbial patterns involves the coordinated action of immune-triggered osmotic changes and actin cytoskeletal remodelling likely driving compact vacuolar morphologies.

show abstract

Section: Introductionmentioning

confidence: 99%

NET4 and RabG3 link actin to the tonoplast and facilitate cytoskeletal remodelling during stomatal immunity

Hawkins,

Kopischke,

Duckney

et al. 2023

Nat Commun

View full text Add to dashboard Cite

show abstract

“…The angles observed at 2-tubule branch points ranged from to less than . These 2-way junctions have been classified as puncta in plant cells 39 , which connect the ER to the plasma membrane 40 , 41 . Given that a branch point between two non-colinear flexible fibres cannot be formed without a third component to balance the forces, this result indicates that the ER forms MCSs with other cellular structures or interacts with microtubules at these branch points.…”

Section: Resultsmentioning

confidence: 99%

Network organisation and the dynamics of tubules in the endoplasmic reticulum

Perkins

Allan

Waigh

2021

Sci Rep

View full text Add to dashboard Cite

The endoplasmic reticulum (ER) is a eukaryotic subcellular organelle composed of tubules and sheet-like areas of membrane connected at junctions. The tubule network is highly dynamic and undergoes rapid and continual rearrangement. There are currently few tools to evaluate network organisation and dynamics. We quantified ER network organisation in Vero and MRC5 cells, and developed an analysis workflow for dynamics of established tubules in live cells. The persistence length, tubule length, junction coordination number and angles of the network were quantified. Hallmarks of imbalances in ER tension, indications of interactions with microtubules and other subcellular organelles, and active dynamics were observed. Clear differences in dynamic behaviour were observed for established tubules at different positions within the cell using itemset mining. We found that tubules with activity-driven fluctuations were more likely to be located away from the cell periphery and a population of peripheral tubules with no signs of active motion was found.

show abstract

“…However, the localization of C22DES in the ER raises the question about how this enzyme can act on the major cellular pool of b-sitosterol present in the PM. It is likely that this process may involve the capacity of the ER to physically interact with the PM at structures known as ER-PM contact sites in which both membranes are in close contact (60)(61)(62). The possibility that enzymes located in one membrane may act on substrates present in a different cell membrane, the so-called in trans activity, is not unprecedented (63)(64)(65)(66).…”

Section: Discussionmentioning

confidence: 99%

Structural and Functional Analysis of Tomato Sterol C22 Desaturase

Gutiérrez-García

Arró

Altabella

et al. 2020

Preprint

View full text Add to dashboard Cite

Background: Sterols are essential components of eukaryotic cells that modulate membrane biophysical properties and function. Plants produce a complex mixture of sterols, among which β-sitosterol, stigmasterol, campesterol, and cholesterol in some Solanaceae, are the most abundant species. Many reports have shown that the stigmasterol to β-sitosterol ratio changes during plant development and in response to stresses, suggesting that it may play a role in the regulation of these processes. In tomato (Solanum lycopersicum), changes in the stigmasterol to β-sitosterol ratio correlate with the induction of the only gene encoding sterol C22-desaturase (C22DES), the enzyme specifically involved in the conversion of β-sitosterol to stigmasterol. However, despite the biological interest of this enzyme, there is still a lack of knowledge about several relevant aspects related to its structure and function.Results: In this study we report the subcellular localization of tomato C22DES in the endoplasmic reticulum (ER) based on confocal fluorescence microscopy and cell fractionation analyses. Modeling studies have also revealed that C22DES consists of two well-differentiated domains: a single N-terminal transmembrane-helix domain (TMH) anchored in the ER-membrane and a globular (or catalytic) domain that is oriented towards the cytosol. Although TMH is sufficient for the targeting and retention of the enzyme in the ER, the globular domain may also interact and be retained in the ER in the absence of the N-terminal transmembrane domain. The observation that a truncated version of C22DES lacking the TMH is enzymatically inactive revealed that the N-terminal membrane domain is essential for enzyme activity. The in silico analysis of the TMH region of plant C22DES revealed several structural features that could be involved in substrate recognition and binding.Conclusions: Overall, this study contributes to expand the current knowledge on the structure and function of plant C22DES and to unveil novel aspects related with plant sterol metabolism.

show abstract

Light microscopy of the endoplasmic reticulum–membrane contact sites in plants

Cited by 10 publications

References 66 publications

NET4 and RabG3 link actin to the tonoplast and facilitate cytoskeletal remodelling during stomatal immunity

NET4 and RabG3 link actin to the tonoplast and facilitate cytoskeletal remodelling during stomatal immunity

Network organisation and the dynamics of tubules in the endoplasmic reticulum

Structural and Functional Analysis of Tomato Sterol C22 Desaturase

Contact Info

Product

Resources

About