scholarly journals Native KCC2 interactome reveals PACSIN1 as a critical regulator of synaptic inhibition

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Vivek Mahadevan ◽  
C Sahara Khademullah ◽  
Zahra Dargaei ◽  
Jonah Chevrier ◽  
Pavel Uvarov ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Hippocampal Neurons ◽  
Regulatory Protein ◽  
Reversal Potential ◽  
Negative Regulator ◽  
Excitatory Synapses ◽  
Receptor Recycling ◽  
The Central Nervous System ◽  
Spine Morphogenesis ◽  
Potent Negative Regulator

KCC2 is a neuron-specific K+-Cl– cotransporter essential for establishing the Cl- gradient required for hyperpolarizing inhibition in the central nervous system (CNS). KCC2 is highly localized to excitatory synapses where it regulates spine morphogenesis and AMPA receptor confinement. Aberrant KCC2 function contributes to human neurological disorders including epilepsy and neuropathic pain. Using functional proteomics, we identified the KCC2-interactome in the mouse brain to determine KCC2-protein interactions that regulate KCC2 function. Our analysis revealed that KCC2 interacts with diverse proteins, and its most predominant interactors play important roles in postsynaptic receptor recycling. The most abundant KCC2 interactor is a neuronal endocytic regulatory protein termed PACSIN1 (SYNDAPIN1). We verified the PACSIN1-KCC2 interaction biochemically and demonstrated that shRNA knockdown of PACSIN1 in hippocampal neurons increases KCC2 expression and hyperpolarizes the reversal potential for Cl-. Overall, our global native-KCC2 interactome and subsequent characterization revealed PACSIN1 as a novel and potent negative regulator of KCC2.

scholarly journals Native KCC2 interactome reveals PACSIN1 as a critical regulator of synaptic inhibition

2017 ◽  
Author(s):  
Vivek Mahadevan ◽  
C. Sahara Khademullah ◽  
Zahra Dargaei ◽  
Jonah Chevrier ◽  
Pavel Uvarov ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Neurological Disorders ◽  
Hippocampal Neurons ◽  
Regulatory Protein ◽  
Reversal Potential ◽  
Negative Regulator ◽  
Excitatory Synapses ◽  
Receptor Recycling ◽  
Spine Morphogenesis ◽  
Potent Negative Regulator

AbstractKCC2 is a neuron-specific K+-Cl− cotransporter essential for establishing the Cl− gradient required for hyperpolarizing inhibition. KCC2 is highly localized to excitatory synapses where it regulates spine morphogenesis and AMPA receptor confinement. Aberrant KCC2 function contributes to numerous human neurological disorders including epilepsy and neuropathic pain. Using unbiased functional proteomics, we identified the KCC2-interactome in the mouse brain to determine KCC2-protein interactions that regulate KCC2 function. Our analysis revealed that KCC2 interacts with a diverse set of proteins, and its most predominant interactors play important roles in postsynaptic receptor recycling. The most abundant KCC2 interactor is a neuronal endocytic regulatory protein termed PACSIN1 (SYNDAPIN1). We verified the PACSIN1-KCC2 interaction biochemically and demonstrated that shRNA knockdown of PACSIN1 in hippocampal neurons significantly increases KCC2 expression and hyperpolarizes the reversal potential for Cl−. Overall, our global native-KCC2 interactome and subsequent characterization revealed PACSIN1 as a novel and potent negative regulator of KCC2.

scholarly journals Synbindin, a Novel Syndecan-2–Binding Protein in Neuronal Dendritic Spines

2000 ◽  
Vol 151 (1) ◽  
pp. 53-68 ◽  
Author(s):  
Iryna M. Ethell ◽  
Kazuki Hagihara ◽  
Yoshiaki Miura ◽  
Fumitoshi Irie ◽  
Yu Yamaguchi
Keyword(s):  
Dendritic Spines ◽  
Membrane Trafficking ◽  
Hippocampal Neurons ◽  
Critical Role ◽  
Postsynaptic Membrane ◽  
Synaptic Membrane ◽  
Excitatory Synapses ◽  
Spine Formation ◽  
Intracellular Vesicles ◽  
Spine Morphogenesis

Dendritic spines are small protrusions on the surface of dendrites that receive the vast majority of excitatory synapses. We previously showed that the cell-surface heparan sulfate proteoglycan syndecan-2 induces spine formation upon transfection into hippocampal neurons. This effect requires the COOH-terminal EFYA sequence of syndecan-2, suggesting that cytoplasmic molecules interacting with this sequence play a critical role in spine morphogenesis. Here, we report a novel protein that binds to the EFYA motif of syndecan-2. This protein, named synbindin, is expressed by neurons in a pattern similar to that of syndecan-2, and colocalizes with syndecan-2 in the spines of cultured hippocampal neurons. In transfected hippocampal neurons, synbindin undergoes syndecan-2–dependent clustering. Synbindin is structurally related to yeast proteins known to be involved in vesicle transport. Immunoelectron microscopy localized synbindin on postsynaptic membranes and intracellular vesicles within dendrites, suggesting a role in postsynaptic membrane trafficking. Synbindin coimmunoprecipitates with syndecan-2 from synaptic membrane fractions. Our results show that synbindin is a physiological syndecan-2 ligand on dendritic spines. We suggest that syndecan-2 induces spine formation by recruiting intracellular vesicles toward postsynaptic sites through the interaction with synbindin.

scholarly journals Specific depletion of the motor protein KIF5B leads to deficits in dendritic transport, synaptic plasticity and memory

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Junjun Zhao ◽  
Albert Hiu Ka Fok ◽  
Ruolin Fan ◽  
Pui-Yi Kwan ◽  
Hei-Lok Chan ◽  
...  
Keyword(s):  
Synaptic Plasticity ◽  
Gene Duplication ◽  
Hippocampal Neurons ◽  
Motor Proteins ◽  
Arginine Methylation ◽  
Memory Formation ◽  
Conditional Knockout ◽  
Excitatory Synapses ◽  
Functional Specificity ◽  
Spine Morphogenesis

The kinesin I family of motor proteins are crucial for axonal transport, but their roles in dendritic transport and postsynaptic function are not well-defined. Gene duplication and subsequent diversification give rise to three homologous kinesin I proteins (KIF5A, KIF5B and KIF5C) in vertebrates, but it is not clear whether and how they exhibit functional specificity. Here we show that knockdown of KIF5A or KIF5B differentially affects excitatory synapses and dendritic transport in hippocampal neurons. The functional specificities of the two kinesins are determined by their diverse carboxyl-termini, where arginine methylation occurs in KIF5B and regulates its function. KIF5B conditional knockout mice exhibit deficits in dendritic spine morphogenesis, synaptic plasticity and memory formation. Our findings provide insights into how expansion of the kinesin I family during evolution leads to diversification and specialization of motor proteins in regulating postsynaptic function.

Three-dimensional structure of dendritic spines, neuronal specializations that impart both stability and flexibility to synaptic function

1993 ◽  
Vol 51 ◽  
pp. 92-93
Author(s):  
Kristen M. Harris
Keyword(s):  
Dendritic Spines ◽  
Three Dimensional ◽  
Synaptic Function ◽  
Dimensional Structure ◽  
Excitatory Synapses ◽  
Concept Of Function ◽  
Section Electron ◽  
High Quality Information ◽  
The Central Nervous System ◽  
Mathematical Analyses

Dendritic spines are the tiny protrusions that stud the surface of many neurons and they are the location of over 90% of all excitatory synapses that occur in the central nervous system. Their small size and variable shapes has in large part made detailed study of their structure refractory to conventional light microscopy and single section electron microscopy (EM). Yet their widespread occurrence and likely involvement in learning and memory has motivated extensive efforts to obtain quantitative descriptions of spines in both steady state and dynamic conditions. Since the seminal mathematical analyses of D’Arcy Thompson, the power of establishing quantitatively key parameters of structure has become recognized as a foundation of successful biological inquiry. For dendritic spines highly precise determinations of structure and its variation are proving themselves as the kingpin for establishing a valid concept of function. The recent conjunction of high quality information about the structure, function, and theoretical implications of dendritic spines has produced a flurry of new considerations of their role in synaptic transmission.

scholarly journals The REG1 Gene Product Is Required for Repression of INO1 and Other Inositol-Sensitive Upstream Activating Sequence-Containing Genes of Yeast

Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Qian Ouyang ◽  
Monica Ruiz-Noriega ◽  
Susan A Henry
Keyword(s):  
Regulatory Protein ◽  
Deletion Mutation ◽  
Negative Regulator ◽  
Regulatory Subunit ◽  
Bhlh Protein ◽  
Gene Products ◽  
Glucose Response ◽  
Upstream Activating Sequence ◽  
Missense Mutant ◽  
Single Base Pair

Abstract A search was conducted for suppressors of the inositol auxotrophic phenotype of the ino4-8 mutant of yeast. The ino4-8 mutation is a single base pair change that results in substitution of lysine for glutamic acid at position 79 in the bHLH domain of the yeast regulatory protein, Ino4p. Ino4p dimerizes with a second bHLH protein, Ino2p, to form a complex that binds to the promoter of the INO1 gene, activating transcription. Of 31 recessive suppressors of ino4-8 isolated, 29 proved to be alleles of a single locus, identified as REG1, which encodes a regulatory subunit of a protein phosphatase involved in the glucose response pathway. The suppressor mutation, sia1-1, identified as an allele of REG1, caused constitutive INO1 expression and was capable of suppressing the inositol auxotrophy of a second ino4 missense mutant, ino4-26, as well as ino2-419, a missense mutation of INO2. The suppressors analyzed were unable to suppress ino2 and ino4 null mutations, but the reg1 deletion mutation could suppress ino4-8. A deletion mutation in the OPI1 negative regulator was incapable of suppressing ino4-8. The relative roles of the OPI1 and REG1 gene products in control of INO1 expression are discussed.

scholarly journals Genetic and Molecular Characterization of the Caenorhabditis elegans Gene, mel-26, a Postmeiotic Negative Regulator of MEI-1, a Meiotic-Specific Spindle Component

Genetics ◽  
1998 ◽  
Vol 150 (1) ◽  
pp. 119-128
Author(s):  
M Rhys Dow ◽  
Paul E Mains
Keyword(s):  
Caenorhabditis Elegans ◽  
Protein Interactions ◽  
Negative Regulator ◽  
Meiotic Spindle ◽  
Loss Of Function ◽  
Protein Protein Interactions ◽  
Gain Of Function ◽  
Recessive Mutations ◽  
Female Germline

Abstract We have previously described the gene mei-1, which encodes an essential component of the Caenorhabditis elegans meiotic spindle. When ectopically expressed after the completion of meiosis, mei-1 protein disrupts the function of the mitotic cleavage spindles. In this article, we describe the cloning and the further genetic characterization of mel-26, a postmeiotic negative regulator of mei-1. mel-26 was originally identified by a gain-of-function mutation. We have reverted this mutation to a loss-of-function allele, which has recessive phenotypes identical to the dominant defects of its gain-of-function parent. Both the dominant and recessive mutations of mel-26 result in mei-1 protein ectopically localized in mitotic spindles and centrosomes, leading to small and misoriented cleavage spindles. The loss-of-function mutation was used to clone mel-26 by transformation rescue. As suggested by genetic results indicating that mel-26 is required only maternally, mel-26 mRNA was expressed predominantly in the female germline. The gene encodes a protein that includes the BTB motif, which is thought to play a role in protein-protein interactions.

scholarly journals Sr2+ and quantal events at excitatory synapses between mouse hippocampal neurons in culture.

1996 ◽  
Vol 495 (1) ◽  
pp. 113-125 ◽  
Author(s):  
M A Abdul-Ghani ◽  
T A Valiante ◽  
P S Pennefather
Keyword(s):  
Hippocampal Neurons ◽  
Excitatory Synapses

scholarly journals Emerging Synaptic Molecules as Candidates in the Etiology of Neurological Disorders

2017 ◽  
Vol 2017 ◽  
pp. 1-25 ◽  
Author(s):  
Viviana I. Torres ◽  
Daniela Vallejo ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Central Nervous System ◽  
Neurological Disorders ◽  
Neuronal Development ◽  
Protein Complexes ◽  
Synaptic Proteins ◽  
Excitatory Synapses ◽  
Complex Structures ◽  
Disease Phenotype ◽  
The Central Nervous System ◽  
Invertebrate Models

Synapses are complex structures that allow communication between neurons in the central nervous system. Studies conducted in vertebrate and invertebrate models have contributed to the knowledge of the function of synaptic proteins. The functional synapse requires numerous protein complexes with specialized functions that are regulated in space and time to allow synaptic plasticity. However, their interplay during neuronal development, learning, and memory is poorly understood. Accumulating evidence links synapse proteins to neurodevelopmental, neuropsychiatric, and neurodegenerative diseases. In this review, we describe the way in which several proteins that participate in cell adhesion, scaffolding, exocytosis, and neurotransmitter reception from presynaptic and postsynaptic compartments, mainly from excitatory synapses, have been associated with several synaptopathies, and we relate their functions to the disease phenotype.

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