scholarly journals Regulation of Melanocortin-5 Receptor Pharmacology by Two Isoforms of MRAP2 in Ricefield Eel (Monopterus albus)

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A508-A508
Author(s):  
Ting Liu ◽  
Ti-Lin Yi ◽  
Dai-Qin Yang ◽  
Ya-Xiong Tao

Abstract The melanocortin-5 receptor (MC5R) has been implicated in the regulation of exocrine gland secretion, immune regulation, and muscle fatty acid oxidation. However, its function in fish is not well established. Melanocortin-2 receptor accessory protein 2 (MRAP2) can modulate trafficking, ligand binding, and signaling of melanocortin receptors. Ricefield eel (Monopterus albus) is an economically and evolutionarily important fish widely distributed in tropics and subtropics. To explore potential interaction between eel MC5R and MRAP2, herein we cloned ricefield eel mc5r, mrap2X1 and mrap2X2. Eel mc5r consisted of a 1056 bp open reading frame encoding a protein of 351 amino acids. Eel mrap2X1 consisted of a 708 bp open reading frame encoding a protein of 235 amino acids, while eel mrap2X2consisted of a 567 bp open reading frame encoding a protein of 188 amino acids. Multiple sequence alignment showed that maMRAP2X1 and maMRAP2X2 shared 90.43% identity. Interestingly, maMRAP2X2 lost the transmembrane domain. Phylogenetic analysis showed that maMC5R and maMRAP2s were closely related to piscine MC5Rs and MRAP2s, respectively. The maMC5R was further demonstrated to be a functional receptor and could be modulated by maMRAP2s in pharmacological studies. Three agonists, [Nle4, D-Phe7]-alpha-melanocyte stimulating hormone (NDP-MSH), alpha-MSH, and adrenocorticotropin (ACTH), could bind to maMC5R and induce intracellular cAMP production dose-dependently. Compared to human MC5R (hMC5R), maMC5R displayed a significantly decreased Bmax but higher binding affinity to alpha-MSH or ACTH. No significant difference in constitutive activity was observed between hMC5R and maMC5R. When stimulated with α-MSH and ACTH, maMC5R showed significantly lower EC50 and Rmax than that of hMC5R. Eel MRAP2s had no effect on cell surface and total expression of maMC5R, whereas they significantly increased Bmax. Only maMRAP2X2 significantly decreased the binding affinity of ACTH. Both maMRAP2X1 and maMRAP2X2 significantly reduced Rmax but did not affect EC50 in response to alpha-MSH or ACTH stimulation. The availability of maMC5R pharmacological characteristics and the modulation by maMRAP2s will facilitate the investigation of its function in regulating diverse physiological processes in ricefield eel.

1991 ◽  
Vol 115 (6) ◽  
pp. 1521-1534 ◽  
Author(s):  
K W Moremen ◽  
P W Robbins

Golgi alpha-mannosidase II (GlcNAc transferase I-dependent alpha 1,3[alpha 1,6] mannosidase, EC 3.2.1.114) catalyzes the final hydrolytic step in the N-glycan maturation pathway acting as the committed step in the conversion of high mannose to complex type structures. We have isolated overlapping clones from a murine cDNA library encoding the full length alpha-mannosidase II open reading frame and most of the 5' and 3' untranslated region. The coding sequence predicts a type II transmembrane protein with a short cytoplasmic tail (five amino acids), a single transmembrane domain (21 amino acids), and a large COOH-terminal catalytic domain (1,124 amino acids). This domain organization which is shared with the Golgi glycosyl-transferases suggests that the common structural motifs may have a functional role in Golgi enzyme function or localization. Three sets of polyadenylated clones were isolated extending 3' beyond the open reading frame by as much as 2,543 bp. Northern blots suggest that these polyadenylated clones totaling 6.1 kb in length correspond to minor message species smaller than the full length message. The largest and predominant message on Northern blots (7.5 kb) presumably extends another approximately 1.4-kb downstream beyond the longest of the isolated clones. Transient expression of the alpha-mannosidase II cDNA in COS cells resulted in 8-12-fold overexpression of enzyme activity, and the appearance of cross-reactive material in a perinuclear membrane array consistent with a Golgi localization. A region within the catalytic domain of the alpha-mannosidase II open reading frame bears a strong similarity to a corresponding sequence in the rat liver endoplasmic reticulum alpha-mannosidase and the vacuolar alpha-mannosidase of Saccharomyces cerevisiae. Partial human alpha-mannosidase II cDNA clones were also isolated and the gene was localized to human chromosome 5.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 481
Author(s):  
Zheng-Yong Wen ◽  
Ting Liu ◽  
Chuan-Jie Qin ◽  
Yuan-Chao Zou ◽  
Jun Wang ◽  
...  

The melanocortin-4 receptor (MC4R) plays an important role in the regulation of food intake and energy expenditure. Melanocortin-2 receptor accessory protein 2 (MRAP2) modulates trafficking, ligand binding, and signaling of MC4R. The Northern snakehead (Channa argus) is an economically important freshwater fish native to East Asia. To explore potential interaction between snakehead MC4R and MRAP2, herein we cloned snakehead mc4r and mrap2. The snakehead mc4r consisted of a 984 bp open reading frame encoding a protein of 327 amino acids, while snakehead mrap2 contained a 693 bp open reading frame encoding a protein of 230 amino acids. Synteny analysis indicated that mc4r was highly conserved with similar gene arrangement, while mrap2 contained two isoforms in teleost with different gene orders. Snakehead mc4r was primarily expressed in the brain, whereas mrap2 was expressed in the brain and intestine. Snakehead mc4r and mrap2 expression was modulated by fasting and refeeding. Further pharmacological experiments showed that the cloned snakehead MC4R was functional, capable of binding to peptide agonists and increasing intracellular cAMP production in a dose-dependent manner. Snakehead MC4R exhibited high constitutive activity. MRAP2 significantly decreased basal and agonist-stimulated cAMP signaling. These findings suggest that snakehead MC4R might be involved in energy balance regulation by interacting with MRAP2. Further studies are needed to elucidate MC4R in regulating diverse physiological processes in snakehead.


1999 ◽  
Vol 73 (6) ◽  
pp. 5123-5131 ◽  
Author(s):  
Blossom Damania ◽  
Mengtao Li ◽  
Joong-Kook Choi ◽  
Louis Alexander ◽  
Jae U. Jung ◽  
...  

ABSTRACT Rhesus monkey rhadinovirus (RRV) is a gamma-2 herpesvirus that is most closely related to the human Kaposi’s sarcoma-associated herpesvirus (KSHV). We have identified a distinct open reading frame at the left end of RRV and designated it R1. The position of the R1 gene is equivalent to that of the saimiri transforming protein (STP) of herpesvirus saimiri (HVS) and of K1 of KSHV, other members of the gamma-2 or rhadinovirus subgroup of herpesviruses. The R1 sequence revealed an open reading frame encoding a product of 423 amino acids that was predicted to contain an extracellular domain, a transmembrane domain, and a C-terminal cytoplasmic tail reflective of a type I membrane-bound protein. The predicted structural motifs of R1, including the presence of immunoreceptor tyrosine-based activation motifs, resembled those in K1 of KSHV but were distinct from those of STP. R1 sequences from four independent isolates from three different macaque species revealed 0.95 to 7.3% divergence over the 423 amino acids. Variation was located predominantly within the predicted extracellular domain. The R1 protein migrated at 70 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and was extensively glycosylated. Tagged R1 protein was localized to the cytoplasmic and plasma membranes of transfected cells. Expression of the R1 gene in Rat-1 fibroblasts induced morphologic changes and focus formation, and injection of R1-expressing cells into nude mice induced the formation of multifocal tumors. A recombinant herpesvirus in which the STP oncogene of HVS was replaced by R1 immortalized T lymphocytes to interleukin-2-independent growth. These results indicate that R1 is an oncogene of RRV.


Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 644-651 ◽  
Author(s):  
Kenneth Koo ◽  
W. Dorsey Stuart

The gene product of the mtr locus of Neurospora crassa is required for the transport of neutral aliphatic and aromatic amino acids via the N system. We have previously cloned three cosmids containing Neurospora DNA that complement the mtr-6(r) mutant allele. The cloned DNAs were tightly linked to restriction fragment length polymorphisms that flank the mtr locus. A 2.9-kbp fragment from one cosmid was subcloned and found to complement the mtr-6(r) allele. Here we report the sequence of the fragment that hybridized to a poly(A)+ mRNA transcript of about 2300 nucleotides. We have identified an 845-bp open reading frame (ORF) having a 59-bp intron as the potential mtr ORF. S1 nuclease analysis of the transcript confirmed the transcript size and the presence of the intron. A second open reading frame was found upstream in the same reading frame as the mtr ORF and appears to be present in the mRNA transcript. The mtr ORF is predicted to encode a 261 amino acid polypeptide with a molecular mass of 28 613 Da. The proposed polypeptide exhibits six potential α-helical transmembrane domains with an average length of 23 amino acids, does not have a signal sequence, and contains amino acid sequence homologous to an RNA binding motif.Key words: sequence, membranes, ribonucleoprotein.


1986 ◽  
Vol 6 (5) ◽  
pp. 1711-1721
Author(s):  
E M McIntosh ◽  
R H Haynes

The dCMP deaminase gene (DCD1) of Saccharomyces cerevisiae has been isolated by screening a Sau3A clone bank for complementation of the dUMP auxotrophy exhibited by dcd1 dmp1 haploids. Plasmid pDC3, containing a 7-kilobase (kb) Sau3A insert, restores dCMP deaminase activity to dcd1 mutants and leads to an average 17.5-fold overproduction of the enzyme in wild-type cells. The complementing activity of the plasmid was localized to a 4.2-kb PvuII restriction fragment within the Sau3A insert. Subcloning experiments demonstrated that a single HindIII restriction site within this fragment lies within the DCD1 gene. Subsequent DNA sequence analysis revealed a 936-nucleotide open reading frame encompassing this HindIII site. Disruption of the open reading frame by integrative transformation led to a loss of enzyme activity and confirmed that this region constitutes the dCMP deaminase gene. Northern analysis indicated that the DCD1 mRNA is a 1.15-kb poly(A)+ transcript. The 5' end of the transcript was mapped by primer extension and appears to exhibit heterogeneous termini. Comparison of the amino acid sequence of the T2 bacteriophage dCMP deaminase with that deduced for the yeast enzyme revealed a limited degree of homology which extends over the entire length of the phage polypeptide (188 amino acids) but is confined to the carboxy-terminal half of the yeast protein (312 amino acids). A potential dTTP-binding site in the yeast and phage enzymes was identified by comparison of homologous regions with the amino acid sequences of a variety of other dTTP-binding enzymes. Despite the role of dCMP deaminase in dTTP biosynthesis, Northern analysis revealed that the DCD1 gene is not subject to the same cell cycle-dependent pattern of transcription recently found for the yeast thymidylate synthetase gene (TMP1).


2000 ◽  
Vol 66 (12) ◽  
pp. 5480-5483 ◽  
Author(s):  
Sean S. Dineen ◽  
Marite Bradshaw ◽  
Eric A. Johnson

ABSTRACT Boticin B is a heat-stable bacteriocin produced byClostridium botulinum strain 213B that has inhibitory activity against various strains of C. botulinum and related clostridia. The gene encoding the bacteriocin was localized to a 3.0-kb HindIII fragment of an 18.8-kb plasmid, cloned, and sequenced. DNA sequencing revealed the boticin B structural gene,btcB, to be an open reading frame encoding 50 amino acids. A C. botulinum strain 62A transconjugant containing theHindIII fragment inserted into a clostridial shuttle vector expressed boticin B, although at much lower levels than those observed in C. botulinum 213B. To our knowledge, this is the first demonstration and characterization of a bacteriocin from toxigenic group I C. botulinum.


1996 ◽  
Vol 16 (8) ◽  
pp. 4222-4230 ◽  
Author(s):  
S J Madigan ◽  
P Edeen ◽  
J Esnayra ◽  
M McKeown

We have identified a gene, alternative testis transcripts (att), which is alternatively expressed, at both the RNA and protein levels, in testes and somatic tissues. The testis-specific RNA differs from somatic RNAs in both promoter usage and RNA processing and is dependent on the function of the transformer 2 gene. The differences between the somatic and testis RNAs have substantial consequences at the protein level. The somatic RNAs encode a protein with homology to the mammalian Graves' disease carrier proteins. The testis RNA lacks the initiation codons used in somatic tissue and encodes two different proteins. One of these begins in a testis-specific exon, uses a reading frame different from that for the somatic protein, and is completely novel. The other protein initiates translation in the frame of the somatic RNA at a Len CUG codon which is within the open reading frame for the somatic protein. This produces a novel truncated version of the Graves' disease carrier protein-like protein that lacks all sequences N terminal to the first transmembrane domain.


Author(s):  
Sirui Yan ◽  
Yulin Wan ◽  
Ying Zhang ◽  
Shanshan An ◽  
Kaiqiao Yang ◽  
...  

The current pneumonia epidemic in China could evolve into a pandemic on a global scale if not effectively contained. The 2019-nCoV possesses a 61-amino acid open reading frame resembling SARS-CoV virulence factor - ORF6 peptide. The isoleucine content is 15.9% in ORF6 of SARS-CoV versus 16.4% of that in 2019-nCoV. Given the proton affinity in the carbonyl oxygen in isoleucine, augmented proton traffic can enhance proton-ion antiport and prompt cell swelling. As the content of essential amino acids in the open reading frame of 2019-nCoV reaches 57.4%, a starch/vitamin diet served for short period of time does not give rise to essential amino acids and halts virion production, which could be adopted as prophylactic approach of many viral infections. Plant-based diet or fasting/boiled rice water can also minimize the intake of essential amino acids or all amino acids respectively. Calorie restriction has been confirmed in animal studies to extend lifespan, and its underlying mechanism is not fully known. Furthermore, several proteins of 2019-nCoV possess high valine plus glycine content, which is implicated in heart disease.


Development ◽  
1991 ◽  
Vol 113 (4) ◽  
pp. 1435-1449 ◽  
Author(s):  
C. Walther ◽  
P. Gruss

A multigene family of paired-box-containing genes (Pax genes) has been identified in the mouse. In this report, we describe the expression pattern of Pax-6 during embryogenesis and the isolation of cDNA clones spanning the entire coding region. The Pax-6 protein consists of 422 amino acids as deduced from the longest open reading frame and contains, in addition to the paired domain, a paired-type homeodomain. Beginning with day 8 of gestation, Pax-6 is expressed in discrete regions of the forebrain and the hindbrain. In the neural tube, expression is mainly confined to mitotic active cells in the ventral ventricular zone along the entire anteroposterior axis starting at day 8.5 of development. Pax-6 is also expressed in the developing eye, the pituitary and the nasal epithelium.


1999 ◽  
Vol 73 (11) ◽  
pp. 9604-9608 ◽  
Author(s):  
Tsutomu Nishizawa ◽  
Hiroaki Okamoto ◽  
Fumio Tsuda ◽  
Tatsuya Aikawa ◽  
Yoshiki Sugai ◽  
...  

ABSTRACT Three hypervariable regions were identified in a central portion of open reading frame 1 of TT virus DNA, which codes for a putative capsid protein of 770 amino acids. TT virus circulates as quasispecies, with many amino acid substitutions in hypervariable regions, to evade immune surveillance of the hosts and to establish a persistent infection.


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