scholarly journals cDNA cloning and localization of Sp3111 (also called Ms4a14) in the rat testis

Reproduction ◽  
2014 ◽  
Vol 148 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Yan Xu ◽  
Miao Liu ◽  
Yi-hua Gu ◽  
Xiao-feng Jia ◽  
Yong-Mei Chen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rna Interference ◽  
Mouse Model ◽  
Protein Level ◽  
Amino Acid Residues ◽  
Immunofluorescence Analysis ◽  
Rat Testis ◽  
Membrane Spanning ◽  
Immunohistochemical Analyses

With tetraspanning topology, members of the membrane-spanning four-domain subfamily A (MS4A) may facilitate signaling or ion channel functions in many tissues. In this study, we report the cloning of a full-length cDNA from rat testis, designatedMs4a14(Sp3111), which encodes the MS4A protein with 1139 amino acid residues.In situhybridization and immunohistochemical analyses indicate thatMs4a14is predominantly expressed from round spermatids to spermatozoa at specific stages in the rat testis at both the mRNA and protein level. Immunofluorescence analysis revealed that MS4A14 (SP3111) is located in the acrosome and the midpiece of the flagellum in mature sperm. Previously, we explored and reported the involvement of MS4A14 in reproductive functions, using antibody blockage during IVF and a transgenic RNA interference method in a mouse model. Our results suggested that MS4A14 is involved in fertilization and zygote division. As MS4A14 protein exists in mammals, such as humans, cows, dogs, and rodents, MS4A14 may play a ubiquitous role in mammalian reproduction.

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 Identification of Amino Acid Residues in the α, β, and γ Subunits of the Epithelial Sodium Channel (ENaC) Involved in Amiloride Block and Ion Permeation

1997 ◽  
Vol 109 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Laurent Schild ◽  
Estelle Schneeberger ◽  
Ivan Gautschi ◽  
Dmitri Firsov
Keyword(s):  
Amino Acid ◽  
Ion Selectivity ◽  
Site Directed Mutagenesis ◽  
Ion Permeation ◽  
Amino Acid Residues ◽  
Α Subunit ◽  
Na Ions ◽  
Membrane Spanning ◽  
A Site ◽  
Epithelial Sodium Channel Enac

The amiloride-sensitive epithelial Nachannel (ENaC) is a heteromultimeric channel made of three αβγ subunits. The structures involved in the ion permeation pathway have only been partially identified, and the respective contributions of each subunit in the formation of the conduction pore has not yet been established. Using a site-directed mutagenesis approach, we have identified in a short segment preceding the second membrane-spanning domain (the pre-M2 segment) amino acid residues involved in ion permeation and critical for channel block by amiloride. Cys substitutions of Gly residues in β and γ subunits at position βG525 and γG537 increased the apparent inhibitory constant (Ki) for amiloride by &gt;1,000-fold and decreased channel unitary current without affecting ion selectivity. The corresponding mutation S583 to C in the α subunit increased amiloride Ki by 20-fold, without changing channel conducting properties. Coexpression of these mutated αβγ subunits resulted in a nonconducting channel expressed at the cell surface. Finally, these Cys substitutions increased channel affinity for block by externalZn2+ ions, in particular the αS583C mutant showing a Ki for Zn2+of 29 μM. Mutations of residues αW582L or βG522D also increased amiloride Ki, the later mutation generating a Ca2+blocking site located 15% within the membrane electric field. These experiments provide strong evidence that αβγ ENaCs are pore-forming subunits involved in ion permeation through the channel. The pre-M2 segment of αβγ subunits may form a pore loop structure at the extracellular face of the channel, where amiloride binds within the channel lumen. We propose that amiloride interacts with Na+ions at an external Na+binding site preventing ion permeation through the channel pore.

scholarly journals Amino Acid Residues Involved in Gating Identified in the First Membrane-spanning Domain of the Rat P2X2Receptor

2001 ◽  
Vol 276 (18) ◽  
pp. 14902-14908 ◽  
Author(s):  
Lin-Hua Jiang ◽  
François Rassendren ◽  
Valeria Spelta ◽  
Annmarie Surprenant ◽  
R. Alan North
Keyword(s):  
Amino Acid ◽  
Amino Acid Residues ◽  
Membrane Spanning

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 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.

scholarly journals The MHC class II-associated invariant chain contains two endosomal targeting signals within its cytoplasmic tail

1993 ◽  
Vol 106 (3) ◽  
pp. 831-846 ◽  
Author(s):  
J. Pieters ◽  
O. Bakke ◽  
B. Dobberstein
Keyword(s):  
Plasma Membrane ◽  
Amino Acid ◽  
Mhc Class Ii ◽  
Cytoplasmic Tail ◽  
Class Ii ◽  
Endocytic Pathway ◽  
Invariant Chain ◽  
Amino Acid Residues ◽  
Marker Proteins ◽  
Membrane Spanning

The oligomeric complex formed by major histocompatibility complex (MHC) class II alpha and beta chains and invariant chain (Ii) assembles in the endoplasmic reticulum and is then transported via the Golgi complex to compartments of the endocytic pathway. When Ii alone is expressed in CV1 cells it is sorted to endosomes. The Ii cytoplasmic tail has been found to be essential for targeting to these compartments. In order to characterize further the signals responsible for endosomal targeting, we have deleted various segments of the cytoplasmic tail. The Ii mutants were transiently expressed and the cellular location of the proteins was analyzed biochemically and morphologically. The cytoplasmic tail of Ii was found to contain two endosomal targeting sequences within its cytoplasmic tail; one targeting sequence was present within amino acid residues 12–29 and deletion of this segment revealed the presence of a second endosomal targeting sequence, located within the first 11 amino acid residues. The presence of a leucine-isoleucine pair at positions 7 and 8 within this sequence was found to be essential for endosomal targeting. In addition, the presence of this L-I motif lead to accumulation of Ii molecules in large endosomal vacuoles containing lysosomal marker proteins. Both wild type Ii and Ii mutant molecules containing only one endosomal targeting sequence were rapidly internalized from the plasma membrane. When the Ii cytoplasmic tail was fused to the membrane-spanning region of neuraminidase, a resident plasma membrane protein, the resulting chimera (INA) was found in endocytic compartments containing lysosomal marker proteins. Thus the cytoplasmic tail of Ii is sufficient for targeting to the endocytic/lysosomal pathway.

Identification of a Novel Gene SRG4 Expressed at Specific Stages of Mouse Spermatogenesis

2004 ◽  
Vol 36 (5) ◽  
pp. 351-359 ◽  
Author(s):  
Xiao-Wei Xing ◽  
Lu-Yun Li ◽  
Gang Liu ◽  
Jun-Jiang Fu ◽  
Xiao-Jun Tan ◽  
...  
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Mouse Testis ◽  
Amino Acid Residues ◽  
Complex Process ◽  
Testis Cdna Library ◽  
New Gene ◽  
Testis Cdna ◽  
Gene 4

Abstract Spermatogenesis is a complex process. Two spermatocytes expression sequence tags (ESTs) BG101130 and BG100990 were found. Their putative amino acid sequences have high homology with rat Spag4 (sperm antigen 4). By electrical hybridization, a novel cDNA encoding polypeptide of 348 amino acid residues was identified from a mouse testis cDNA library. The new gene was designated as SRG4 (Spermatogenesis related gene 4) (GenBank accession No. AY307077). Results of Northern blot and RTPCR revealed that SRG4 expressed specifically in mouse testis. Changes of SRG4 expression in mouse different development stages were observed by RT-PCR. The SRG4 mRNA was hardly detected in 2 weeks postpartum, and expressed abundantly from 3 weeks later, reaching top lever at 4–5 weeks, while slightly down in aging mouse testis. Results of in situ hybridization showed that SRG4 gene expressed abundantly in spermatocytes, round spermatids. This indicated SRG4 gene may play an important role in mouse meiotic divisions of spermatocytes.

scholarly journals Molecular Cloning of a Novel Mouse Testis-specific Spermatogenic Cell Apoptosis Inhibitor Gene mTSARG7 as a Candidate Oncogene

2005 ◽  
Vol 37 (6) ◽  
pp. 396-405 ◽  
Author(s):  
Xiao-Jun Tan ◽  
Xiao-Wei Xing ◽  
Lu-Yun Li ◽  
Zhao-Di Wu ◽  
Chang-Gao Zhong ◽  
...  
Keyword(s):  
Amino Acid ◽  
Mrna Expression ◽  
Expressed Sequence Tag ◽  
Mouse Testis ◽  
Control Group ◽  
Amino Acid Residues ◽  
Apoptosis Inhibitor ◽  
Expressed Sequence ◽  
Candidate Oncogene

Abstract A novel mouse gene, mTSARG7 (GenBank accession No. AY489184), with a full cDNA length of 2279 bp and containing 12 exons and 11 introns, was cloned from a mouse expressed sequence tag (GenBank accession No. BE644543) that was significantly up-regulated in cryptorchidism. The gene was located in mouse chromosome 8A1.3 and encoded a protein containing 403 amino acid residues that was a new member of the acyltransferase family because the sequence contained the highly conserved phosphate acyltransferase (PlsC) domain existing in all acyltransferase-like proteins. The mTSARG7 protein and AU041707 protein shared 83.9% identity in 402 amino acid residues. Expression of the mTSARG7 gene was restricted to the mouse testis. The results of the in situ hybridization analysis revealed that the mTSARG7 mRNA was expressed in mouse spermatogonia and spermatocytes. Subcellular localization studies showed that the EGFP-tagged mTSARG7 protein was localized in the cytoplasm of GC-1 spg cells. The mTSARG7 mRNA expression was initiated in the mouse testis in the second week after birth, and the expression level increased steadily with spermatogenesis and sexual maturation of the mouse. The results of the heat stress experiment showed that the mTSARG7 mRNA expression gradually decreased as the heating duration increased. The pcDNA3.1 Hygro(–)/mTSARG7 plasmid was constructed and introduced into GC-1 spg cells by liposome transfection. The mTSARG7 can accelerate GC-1 spg cells, causing them to traverse the S-phase and enter the G2-phase, compared with the control group where this did not occur as there was no transfection of mTSARG7. In conclusion, our results suggest that this gene may play an important role in spermatogenesis and the development of cryptorchid testes, and is a testis-specific apoptosis candidate oncogene.

scholarly journals The human collagen X gene. Complete primary translated sequence and chromosomal localization

1991 ◽  
Vol 280 (3) ◽  
pp. 617-623 ◽  
Author(s):  
J T Thomas ◽  
C J Cresswell ◽  
B Rash ◽  
H Nicolai ◽  
T Jones ◽  
...  
Keyword(s):  
Amino Acid ◽  
Chromosomal Localization ◽  
Amino Acid Residues ◽  
Untranslated Sequence ◽  
Human Collagen ◽  
Hybridization In Situ ◽  
X Gene ◽  
Triple Helical Domain ◽  
Collagenous Domain

We report on the complete primary translated sequence of human alpha 1(X) collagen, deduced from a genomic clone, and the chromosomal localization of the human collagen X gene. The primary translated product of human collagen X is encoded by two exons of 169 bp and approx. 2940 bp. The 169 bp exon encodes 15 bp of 5′-end untranslated sequence, 18 amino acid residues (54 bp) of signal peptide and 33 1/3 amino acid residues (100 bp) of the N-terminal non-collagenous domain. The 2940 bp exon encodes 4 2/3 amino acid residues (14 bp) of the N-terminal non-collagenous domain, the complete triple-helical domain of 463 amino acid residues (1389 bp), the complete C-terminal non-collagenous domain of 161 amino acid residues (483 bp) and 1054 bp of 3′-end untranslated sequence up to and including a potential cleavage/polyadenylation signal. The size of the intron separating the two exons, as estimated by partial sequencing and Southern-blot analyses, is approx. 3200 bp. By a combination of somatic cell hybrid screening and hybridization in situ the human collagen X gene (COL10A1) has been assigned to the distal end of the long arm of chromosome 6 at the locus 6q21-6q22.3.

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