scholarly journals Expression and distribution of synaptotagmin isoforms in the zebrafish retina

2020 ◽  
Author(s):  
Diane Henry ◽  
Christina Joselevitch ◽  
Gary G. Matthews ◽  
Lonnie P. Wollmuth
Keyword(s):  
Amino Acid ◽  
Large Family ◽  
Amino Acid Residues ◽  
Ribbon Synapses ◽  
The Family ◽  
Class 1 ◽  
The Central Nervous System ◽  
Asynchronous Release ◽  
The Brain

ABSTRACTSynaptotagmins belong to a large family of proteins. While various synaptotagmins have been implicated as Ca2+ sensors for vesicle replenishment and release at conventional synapses, their roles at retinal ribbon synapses remain incompletely understood. Zebrafish is a widely used experimental model for retinal research. We therefore investigated the homology between human, rat, mouse, and zebrafish synaptotagmins 1 to 10 using a bioinformatics approach. We also characterized the expression and distribution of various synaptotagmin (syt) genes in the zebrafish retina using RT-PCR and in situ hybridization, focusing on the family members whose products likely underlie Ca2+-dependent exocytosis in the central nervous system (synaptotagmins 1, 2, 5 and 7). We find that most zebrafish synaptotagmins are well conserved and can be grouped in the same classes as mammalian synaptotagmins, based on crucial amino acid residues needed for coordinating Ca2+ binding and determining phospholipid binding affinity. The only exception is synaptotagmin 1b, which lacks 34 amino acid residues in the C2B domain and is therefore unlikely to bind Ca2+ there. Additionally, the products of zebrafish syt5a and syt5b genes share identity with mammalian class 1 and 5 synaptotagmins. Zebrafish syt1, syt2, syt5 and syt7 paralogues are found in the zebrafish brain, eye, and retina, excepting syt1b, which is only present in the brain. The complementary expression pattern of the remaining paralogues in the retina suggests that syt1a and syt5a may underlie synchronous release and syt7a and syt7b may mediate asynchronous release or other Ca2+ dependent processes in different types of retinal neurons.

Mouse Wnt genes exhibit discrete domains of expression in the early embryonic CNS and limb buds

Development ◽  
1993 ◽  
Vol 119 (1) ◽  
pp. 247-261 ◽  
Author(s):  
B.A. Parr ◽  
M.J. Shea ◽  
G. Vassileva ◽  
A.P. McMahon
Keyword(s):  
Limb Development ◽  
Expression Patterns ◽  
Limb Buds ◽  
Expression Studies ◽  
The Family ◽  
The Central Nervous System ◽  
Discrete Domains ◽  
Early Developmental ◽  
The Brain

Mutation and expression studies have implicated the Wnt gene family in early developmental decision making in vertebrates and flies. In a detailed comparative analysis, we have used in situ hybridization of 8.0- to 9.5-day mouse embryos to characterize expression of all ten published Wnt genes in the central nervous system (CNS) and limb buds. Seven of the family members show restricted expression patterns in the brain. At least three genes (Wnt-3, Wnt-3a, and Wnt-7b) exhibit sharp boundaries of expression in the forebrain that may predict subdivisions of the region later in development. In the spinal cord, Wnt-1, Wnt-3, and Wnt-3a are expressed dorsally, Wnt-5a, Wnt-7a, and Wnt-7b more ventrally, and Wnt-4 both dorsally and in the floor plate. In the forelimb primordia, Wnt-3, Wnt-4, Wnt-6 and Wnt-7b are expressed fairly uniformly throughout the limb ectoderm. Wnt-5a RNA is distributed in a proximal to distal gradient through the limb mesenchyme and ectoderm. Along the limb's dorsal-ventral axis, Wnt-5a is expressed in the ventral ectoderm and Wnt-7a in the dorsal ectoderm. We discuss the significance of these patterns of restricted and partially overlapping domains of expression with respect to the putative function of Wnt signalling in early CNS and limb development.

scholarly journals How [FeFe]-Hydrogenase Facilitates Bidirectional Proton Transfer

2019 ◽  
Author(s):  
Moritz Senger ◽  
Viktor Eichmann ◽  
Konstantin Laun ◽  
Jifu Duan ◽  
Florian Wittkamp ◽  
...  
Keyword(s):  
Amino Acid ◽  
Proton Transfer ◽  
Active Site ◽  
Molecular Hydrogen ◽  
H2 Production ◽  
Amino Acid Residues ◽  
Difference Spectroscopy ◽  
Dynamic Changes ◽  
In Situ Ir

Hydrogenases are metalloenzymes that catalyse the interconversion of protons and molecular hydrogen, H2. [FeFe]-hydrogenases show particularly high rates of hydrogen turnover and have inspired numerous compounds for biomimetic H2 production. Two decades of research on the active site cofactor of [FeFe]-hydrogenases have put forward multiple models of the catalytic proceedings. In comparison, understanding of the catalytic proton transfer is poor. We were able to identify the amino acid residues forming a proton transfer pathway between active site cofactor and bulk solvent; however, the exact mechanism of catalytic proton transfer remained inconclusive. Here, we employ in situ IR difference spectroscopy on the [FeFe]-hydrogenase from Chlamydomonas reinhardtii evaluating dynamic changes in the hydrogen-bonding network upon catalytic proton transfer. Our analysis allows for a direct, molecular unique assignment to individual amino acid residues. We found that transient protonation changes of arginine and glutamic acid residues facilitate bidirectional proton transfer in [FeFe]-hydrogenases.<br>

scholarly journals Characterization and Incidence of the First Member of the Genus Mitovirus Identified in the Phytopathogenic Species Fusarium oxysporum

Viruses ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 279 ◽  
Author(s):  
Almudena Torres-Trenas ◽  
Encarnación Pérez-Artés
Keyword(s):  
Phylogenetic Analysis ◽  
Amino Acid ◽  
Genetic Code ◽  
Fusarium Oxysporum ◽  
Amino Acid Residues ◽  
Fusarium Spp ◽  
Stem Loop ◽  
Universal Genetic Code ◽  
The Family ◽  
Amino Acid Tryptophan

A novel mycovirus named Fusarium oxysporum f. sp. dianthi mitovirus 1 (FodMV1) has been identified infecting a strain of Fusarium oxysporum f. sp. dianthi from Colombia. The genome of FodMV1 is 2313 nt long, and comprises a 172-nt 5’-UTR, a 2025-nt single ORF encoding an RdRp of 675 amino acid residues, and a 113-nt 3´-UTR. Homology BlastX searches identifies FodMV1 as a novel member of the genus Mitovirus in the family Narnaviridae. As the rest of mitoviruses, the genome of FodMV1 presents a high percentage of A+U (58.8%) and contains a number of UGA codons that encode the amino acid tryptophan rather than acting as stop codons as in the universal genetic code. Another common feature with other mitoviruses is that the 5′- and 3′-UTR regions of FodMV1 can be folded into potentially stable stem-loop structures. Result from phylogenetic analysis place FodMV1 in a different clade than the rest of mitoviruses described in other Fusarium spp. Incidence of FodMV1-infections in the collection of F. oxysporum f. sp. dianthi isolates analyzed is relatively high. Of particular interest is the fact that FodMV1 has been detected infecting isolates from two geographical areas as distant as Spain and Colombia.

scholarly journals Peptidase E, a Peptidase Specific for N-Terminal Aspartic Dipeptides, Is a Serine Hydrolase

2000 ◽  
Vol 182 (9) ◽  
pp. 2536-2543 ◽  
Author(s):  
Rachel A. L. Lassy ◽  
Charles G. Miller
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Site Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Serine Hydrolase ◽  
Genome Sequences ◽  
New Family ◽  
The Family ◽  
Serovar Typhimurium ◽  
Structural Classes

ABSTRACT Salmonella enterica serovar Typhimurium peptidase E (PepE) is an N-terminal Asp-specific dipeptidase. PepE is not inhibited by any of the classical peptidase inhibitors, and its amino acid sequence does not place it in any of the known peptidase structural classes. A comparison of the amino acid sequence of PepE with a number of related sequences has allowed us to define the amino acid residues that are strongly conserved in this family. To ensure the validity of this comparison, we have expressed one of the most distantly related relatives (Xenopus) in Escherichia coli and have shown that it is indeed an Asp-specific dipeptidase with properties very similar to those of serovar Typhimurium PepE. The sequence comparison suggests that PepE is a serine hydrolase. We have used site-directed mutagenesis to change all of the conserved Ser, His, and Asp residues and have found that Ser120, His157, and Asp135 are all required for activity. Conversion of Ser120 to Cys leads to severely reduced (104-fold) but still detectable activity, and this activity but not that of the parent is inhibited by thiol reagents; these results confirm that this residue is likely to be the catalytic nucleophile. These results suggest that PepE is the prototype of a new family of serine peptidases. The phylogenetic distribution of the family is unusual, since representatives are found in eubacteria, an insect (Drosophila), and a vertebrate (Xenopus) but not in the Archaea or in any of the other eukaryotes for which genome sequences are available.

scholarly journals Neuronal MCP-1 Expression in Response to Remote Nerve Injury

2001 ◽  
Vol 21 (1) ◽  
pp. 69-76 ◽  
Author(s):  
Alexander Flügel ◽  
Gerhard Hager ◽  
Andrea Horvat ◽  
Christoph Spitzer ◽  
Gamal M. A. Singer ◽  
...  
Keyword(s):  
T Cell ◽  
Inflammatory Responses ◽  
Nerve Lesion ◽  
Monocyte Chemoattractant ◽  
Direct Injury ◽  
Inflammatory Activation ◽  
The Central Nervous System ◽  
Inducible Protein ◽  
The Brain

Direct injury of the brain is followed by inflammatory responses regulated by cytokines and chemoattractants secreted from resident glia and invading cells of the peripheral immune system. In contrast, after remote lesion of the central nervous system, exemplified here by peripheral transection or crush of the facial and hypoglossal nerve, the locally observed inflammatory activation is most likely triggered by the damaged cells themselves, that is, the injured neurons. The authors investigated the expression of the chemoattractants monocyte chemoattractant protein MCP-1, regulation on activation normal T-cell expressed and secreted (RANTES), and interferon-gamma inducible protein IP10 after peripheral nerve lesion of the facial and hypoglossal nuclei. In situ hybridization and immunohistochemistry revealed an induction of neuronal MCP-1 expression within 6 hours postoperation, reaching a peak at 3 days and remaining up-regulated for up to 6 weeks. MCP-1 expression was almost exclusively confined to neurons but was also present on a few scattered glial cells. The authors found no alterations in the level of expression and cellular distribution of RANTES or IP10, which were both confined to neurons. Protein expression of the MCP-1 receptor CCR2 did not change. MCP-1, expressed by astrocytes and activated microglia, has been shown to be crucial for monocytic, or T-cell chemoattraction, or both. Accordingly, expression of MCP-1 by neurons and its corresponding receptor in microglia suggests that this chemokine is involved in neuron and microglia interaction.

scholarly journals Coexpression of Corticotropin-Releasing Hormone and Urotensin I Precursor Genes in the Caudal Neurosecretory System of the Euryhaline Flounder (Platichthys flesus): A Possible Shared Role in Peripheral Regulation

Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5786-5797 ◽  
Author(s):  
Weiqun Lu ◽  
Louise Dow ◽  
Sarah Gumusgoz ◽  
Matthew J. Brierley ◽  
Justin M. Warne ◽  
...  
Keyword(s):  
Amino Acid ◽  
Adaptive Plasticity ◽  
Neurosecretory System ◽  
Amino Acid Residues ◽  
Major Site ◽  
Caudal Neurosecretory System ◽  
Genes Encoding ◽  
Releasing Factors ◽  
Circulating Levels

Abstract CRH and urotensin I (UI) are neuroendocrine peptides that belong to the superfamily of corticotropin-releasing factors. In mammals, these peptides regulate the stress response and other central nervous system functions, whereas in fish an involvement for UI in osmoregulation has also been suggested. We have identified, characterized, and localized the genes encoding these peptides in a unique fish neuroendocrine organ, the caudal neurosecretory system (CNSS). The CRH and UI precursors, isolated from a European flounder CNSS library, consist of 168 and 147 amino acid residues, respectively, with an overall homology of approximately 50%. Both precursors contain a signal peptide, a divergent cryptic region and a 41-amino acid mature peptide with cleavage and amidation sites. Genomic organization showed that whole CRH and UI coding sequences are contained in a single exon. Northern blot analysis and quantitative PCR of a range of tissues confirmed the CNSS as a major site of expression of both CRH and UI and thus serves as a likely source of circulating peptides. In situ hybridization demonstrated that CRH and UI colocalize to the same cells of the CNSS. Our findings suggest that, in euryhaline fish, the CNSS is a major site of production of CRH and probably contributes to the high circulating levels observed in response to specific environmental challenges. Furthermore, the localization of CRH and UI within the same cell population suggests an early, possibly shared role for these peptides in controlling stress-mediated adaptive plasticity.

scholarly journals Pool of endoglucanase genes in Schizophyllum commune Fr.:Fr. (Basidiomycetes) on the territory of Ukraine

2018 ◽  
Vol 62 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Sergiy M. Boiko
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Polymorphic Locus ◽  
Schizophyllum Commune ◽  
Amino Acid Residues ◽  
The Family

Pool of intracellular endoglucanases of the fungus Schizophyllum commune on the territory of Ukraine was studied. Two loci of endoglucanase (Eg1, Eg2) were found. The polymorphic locus Eg2 controls the expression of four alleles. Alleles Eg293, Eg296 and Eg2102 are rare and peculiar to certain populations. Amino acid sequence of the locus Eg2 in databases of NCBI (XP_003031634.1) and UniProt (D8Q439) was probably identified. It is classified among the family 5 (GH5) and consists of 333 amino acid residues.

scholarly journals Macrophages Are Dispensable for Postnatal Pruning of the Cochlear Ribbon Synapses

2021 ◽  
Vol 15 ◽  
Author(s):  
Chaorong Yu ◽  
Hui-Ming Gao ◽  
Guoqiang Wan
Keyword(s):  
Hair Cells ◽  
Cochlear Hair Cells ◽  
Ribbon Synapses ◽  
The Central Nervous System ◽  
Complement Receptor 3 ◽  
Auditory Functions ◽  
The Complement System ◽  
The Brain ◽  
Synaptic Pruning ◽  
Genetic Mouse Models

Ribbon synapses of cochlear hair cells undergo pruning and maturation before the hearing onset. In the central nervous system (CNS), synaptic pruning was mediated by microglia, the brain-resident macrophages, via activation of the complement system. Whether a similar mechanism regulates ribbon synapse pruning is currently unknown. In this study, we report that the densities of cochlear macrophages surrounding hair cells were highest at around P8, corresponding well to the completion of ribbon synaptic pruning by P8–P9. Surprisingly, using multiple genetic mouse models, we found that postnatal pruning of the ribbon synapses and auditory functions were unaffected by the knockout of the complement receptor 3 (CR3) or by ablations of macrophages expressing either LysM or Cx3cr1. Our results suggest that unlike microglia in the CNS, macrophages in the cochlea do not mediate pruning of the cochlear ribbon synapses.

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