scholarly journals Small peptides modulate the immune function of the ion channel-like protein ACD6 in Arabidopsis thaliana

2021 ◽  
Author(s):  
Wangsheng Zhu ◽  
Lei Li ◽  
Benjamin Neuhäuser ◽  
Michael Thelen ◽  
Mingyu Wang ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Transient Receptor Potential ◽  
Transmembrane Protein ◽  
Quantitative Resistance ◽  
Plant Immunity ◽  
Receptor Potential ◽  
Ankyrin Repeats ◽  
Small Peptides ◽  
Wild Strains ◽  
Transient Receptor

AbstractThe quantitative resistance gene ACCELERATED CELL DEATH 6 (ACD6), which encodes a transmembrane protein with intracellular ankyrin repeats, has been implicated in a trade-off between growth and defense among wild strains of Arabidopsis thaliana. Naturally hyperactive alleles of the ACD6-Est-1 type can lead to spontaneous activation of immune responses, although the extent of visible hyperimmunity in strains with this allele varies substantially. We have identified a natural suppressor locus, MODULATOR OF HYPERACTIVE ACD6 1 (MHA1), which codes for a small protein of ~7 kDa that attenuates activity of the ACD6-Est-1 allele. MHA1 and its paralog MHA1-LIKE (MHAL) differentially interact with specific ACD6 variants, and both MHA1 and MHAL peptides can bind to the ACD6 ankyrin repeats. MHAL also enhances accumulation of an ACD6 complex, thereby increasing activity of the ACD6 standard allele. The ACD6 ankyrin repeats are similar to those of transient receptor potential (TRP) ion channels, and several lines of evidence support that increased ACD6 activity is linked to enhanced calcium signaling. Our work highlights how the study of natural variation reveals new aspects of plant immunity.

scholarly journals Steroids and TRP Channels: A Close Relationship

2020 ◽  
Vol 21 (11) ◽  
pp. 3819
Author(s):  
Karina Angélica Méndez-Reséndiz ◽  
Óscar Enciso-Pablo ◽  
Ricardo González-Ramírez ◽  
Rebeca Juárez-Contreras ◽  
Tamara Rosenbaum ◽  
...  
Keyword(s):  
Transient Receptor Potential ◽  
Cell Function ◽  
Trp Channels ◽  
Protein Complexes ◽  
Transmembrane Protein ◽  
Receptor Potential ◽  
Long Term Effects ◽  
Close Relationship ◽  
Transient Receptor

Transient receptor potential (TRP) channels are remarkable transmembrane protein complexes that are essential for the physiology of the tissues in which they are expressed. They function as non-selective cation channels allowing for the signal transduction of several chemical, physical and thermal stimuli and modifying cell function. These channels play pivotal roles in the nervous and reproductive systems, kidney, pancreas, lung, bone, intestine, among others. TRP channels are finely modulated by different mechanisms: regulation of their function and/or by control of their expression or cellular/subcellular localization. These mechanisms are subject to being affected by several endogenously-produced compounds, some of which are of a lipidic nature such as steroids. Fascinatingly, steroids and TRP channels closely interplay to modulate several physiological events. Certain TRP channels are affected by the typical genomic long-term effects of steroids but others are also targets for non-genomic actions of some steroids that act as direct ligands of these receptors, as will be reviewed here.

scholarly journals Functional Importance of Transient Receptor Potential (TRP) Channels in Neurological Disorders

2021 ◽  
Vol 9 ◽  
Author(s):  
Kihwan Lee ◽  
Youn Yi Jo ◽  
Gehoon Chung ◽  
Jung Hoon Jung ◽  
Yong Ho Kim ◽  
...  
Keyword(s):  
Neurological Disorders ◽  
Transient Receptor Potential ◽  
Trp Channels ◽  
Protein Complexes ◽  
Transmembrane Protein ◽  
Second Messengers ◽  
Ion Homeostasis ◽  
Receptor Potential ◽  
Functional Roles ◽  
Transient Receptor

Transient receptor potential (TRP) channels are transmembrane protein complexes that play important roles in the physiology and pathophysiology of both the central nervous system (CNS) and the peripheral nerve system (PNS). TRP channels function as non-selective cation channels that are activated by several chemical, mechanical, and thermal stimuli as well as by pH, osmolarity, and several endogenous or exogenous ligands, second messengers, and signaling molecules. On the pathophysiological side, these channels have been shown to play essential roles in the reproductive system, kidney, pancreas, lung, bone, intestine, as well as in neuropathic pain in both the CNS and PNS. In this context, TRP channels have been implicated in several neurological disorders, including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, and epilepsy. Herein, we focus on the latest involvement of TRP channels, with a special emphasis on the recently identified functional roles of TRP channels in neurological disorders related to the disruption in calcium ion homeostasis.

scholarly journals Transcriptomic Profiling of Ca2+ Transport Systems during the Formation of the Cerebral Cortex in Mice

Cells ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1800
Author(s):  
Alexandre Bouron
Keyword(s):  
Cerebral Cortex ◽  
Plasma Membrane ◽  
Transient Receptor Potential ◽  
Transmembrane Protein ◽  
Receptor Potential ◽  
Cytosolic Calcium ◽  
Cation Channel ◽  
Transport Systems ◽  
Transcriptomic Profiling ◽  
Transient Receptor

Cytosolic calcium (Ca2+) transients control key neural processes, including neurogenesis, migration, the polarization and growth of neurons, and the establishment and maintenance of synaptic connections. They are thus involved in the development and formation of the neural system. In this study, a publicly available whole transcriptome sequencing (RNA-Seq) dataset was used to examine the expression of genes coding for putative plasma membrane and organellar Ca2+-transporting proteins (channels, pumps, exchangers, and transporters) during the formation of the cerebral cortex in mice. Four ages were considered: embryonic days 11 (E11), 13 (E13), and 17 (E17), and post-natal day 1 (PN1). This transcriptomic profiling was also combined with live-cell Ca2+ imaging recordings to assess the presence of functional Ca2+ transport systems in E13 neurons. The most important Ca2+ routes of the cortical wall at the onset of corticogenesis (E11–E13) were TACAN, GluK5, nAChR β2, Cav3.1, Orai3, transient receptor potential cation channel subfamily M member 7 (TRPM7) non-mitochondrial Na+/Ca2+ exchanger 2 (NCX2), and the connexins CX43/CX45/CX37. Hence, transient receptor potential cation channel mucolipin subfamily member 1 (TRPML1), transmembrane protein 165 (TMEM165), and Ca2+ “leak” channels are prominent intracellular Ca2+ pathways. The Ca2+ pumps sarco/endoplasmic reticulum Ca2+ ATPase 2 (SERCA2) and plasma membrane Ca2+ ATPase 1 (PMCA1) control the resting basal Ca2+ levels. At the end of neurogenesis (E17 and onward), a more numerous and diverse population of Ca2+ uptake systems was observed. In addition to the actors listed above, prominent Ca2+-conducting systems of the cortical wall emerged, including acid-sensing ion channel 1 (ASIC1), Orai2, P2X2, and GluN1. Altogether, this study provides a detailed view of the pattern of expression of the main actors participating in the import, export, and release of Ca2+. This work can serve as a framework for further functional and mechanistic studies on Ca2+ signaling during cerebral cortex formation.

Structure–functional intimacies of transient receptor potential channels

2009 ◽  
Vol 42 (3) ◽  
pp. 201-246 ◽  
Author(s):  
Ramon Latorre ◽  
Cristián Zaelzer ◽  
Sebastian Brauchi
Keyword(s):  
Transient Receptor Potential ◽  
Trp Channels ◽  
Transmembrane Protein ◽  
Receptor Potential ◽  
Transient Receptor Potential Channels ◽  
Trp Channel ◽  
Structural Determinants ◽  
Structure Information ◽  
High Calcium ◽  
Transient Receptor

AbstractAlthough a unifying characteristic common to all transient receptor potential (TRP) channel functions remains elusive, they could be described as tetramers formed by subunits with six transmembrane domains and containing cation-selective pores, which in several cases show high calcium permeability. TRP channels constitute a large superfamily of ion channels, and can be grouped into seven subfamilies based on their amino acid sequence homology: the canonical or classic TRPs, the vanilloid receptor TRPs, the melastatin or long TRPs, ankyrin (whose only member is the transmembrane protein 1 [TRPA1]), TRPN after the nonmechanoreceptor potential C (nonpC), and the more distant cousins, the polycystins and mucolipins. Because of their role as cellular sensors, polymodal activation and gating properties, many TRP channels are activated by a variety of different stimuli and function as signal integrators. Thus, how TRP channels function and how function relates to given structural determinants contained in the channel-forming protein has attracted the attention of biophysicists as well as molecular and cell biologists. The main purpose of this review is to summarize our present knowledge on the structure of channels of the TRP ion channel family. In the absence of crystal structure information for a complete TRP channel, we will describe important protein domains present in TRP channels, structure–function mutagenesis studies, the few crystal structures available for some TRP channel modules, and the recent determination of some TRP channel structures using electron microscopy.

Inositol lipids and TRPC channel activation

2007 ◽  
Vol 74 ◽  
pp. 37-45 ◽  
Author(s):  
James W. Putney
Keyword(s):  
Plasma Membrane ◽  
Phospholipase C ◽  
Transient Receptor Potential ◽  
Calcium Signalling ◽  
Receptor Potential ◽  
Breakdown Product ◽  
Channel Activation ◽  
Inositol Lipids ◽  
Transient Receptor ◽  
Secondary Mechanism

The original hypothesis put forth by Bob Michell in his seminal 1975 review held that inositol lipid breakdown was involved in the activation of plasma membrane calcium channels or ‘gates’. Subsequently, it was demonstrated that while the interposition of inositol lipid breakdown upstream of calcium signalling was correct, it was predominantly the release of Ca2+ that was activated, through the formation of Ins(1,4,5)P3. Ca2+ entry across the plasma membrane involved a secondary mechanism signalled in an unknown manner by depletion of intracellular Ca2+ stores. In recent years, however, additional non-store-operated mechanisms for Ca2+ entry have emerged. In many instances, these pathways involve homologues of the Drosophila trp (transient receptor potential) gene. In mammalian systems there are seven members of the TRP superfamily, designated TRPC1–TRPC7, which appear to be reasonably close structural and functional homologues of Drosophila TRP. Although these channels can sometimes function as store-operated channels, in the majority of instances they function as channels more directly linked to phospholipase C activity. Three members of this family, TRPC3, 6 and 7, are activated by the phosphoinositide breakdown product, diacylglycerol. Two others, TRPC4 and 5, are also activated as a consequence of phospholipase C activity, although the precise substrate or product molecules involved are still unclear. Thus the TRPCs represent a family of ion channels that are directly activated by inositol lipid breakdown, confirming Bob Michell's original prediction 30 years ago.

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