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Query: UNIPROT:P01189 (
beta-endorphin
)
21,003
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
The antinociceptive effect of intracerebroventricular injection (icv) of
Asn
-Ala-Gly-Ala (NAGA), a partial sequence of beta-lipotropin, was studied in rats. The potassium iontophoresis-induced tail flick was used to measure the pain threshold. The antinociceptive effect of NAGA, which was dose-dependent (icv, 0.03-0.24 mumol/rat) and long-lasting (90 min), was reversed by naloxone (icv, 0.26 mg.kg-1) and inhibited by anti-MEK serum (titre: 1:5000, 5 microliters) or anti-LEK serum (titre: 1:5000, 5 microliters). NAGA-induced antinociception was scarcely affected by anti-beta-EP serum (titre: 1:30,000, 5 microliters) or anti-Dyn A1-13 serum (titre: 1:30,000, 5 microliters). It was suggested that the antinociceptive effect of NAGA may be associated with the release of
met-enkephalin
and leu-enkephalin in rat brain.
...
PMID:Antinociceptive effect of intracerebroventricular injection of a tetrapeptide Asn-Ala-Gly-Ala in rats. 770 46
Differential expression of glycosyltransferases has the potential to generate functionally distinct glycoforms of otherwise identical proteins. We have previously demonstrated the presence of unique oligosaccharides terminating with GalNAc-4-SO4 on the pituitary glycoproteins lutropin (LH), thyroid stimulating hormone (TSH), and
pro-opiomelanocortin (POMC)
. A glycoprotein hormone:GalNAc-transferase and a GalNAc-4-sulfotransferase are present in the pituitary and can account for the synthesis of these unique oligosaccharides on specific glycoproteins. Both transferases are coordinately expressed in a number of tissues in addition to pituitary, including submaxillary gland, lacrimal gland, and kidney, suggesting that additional glycoproteins bearing oligosaccharides terminating with GalNAc-4-SO4 are synthesized in these tissues. In this study we show that while the glycoprotein hormone:GalNAc-transferase and the GalNAc-4-sulfotransferase are coordinately expressed in bovine submaxillary gland, the GalNAc-transferase is expressed in the parotid gland in the absence of the GalNAc-4-sulfotransferase. The relative expression of these two transferases in submaxillary and parotid glands correlates with the presence of unique
Asn
-linked oligosaccharides on carbonic anhydrase VI (CA VI) synthesized in each of these tissues. The majority of
Asn
-linked oligosaccharides on CA VI synthesized in submaxillary gland terminate with GalNAc-4-SO4. In contrast, CA VI which is synthesized in bovine parotid gland bears oligosaccharides which terminate predominantly with beta 1,4-linked GalNAc which is not sulfated. The presence of different terminal residues on the
Asn
-linked oligosaccharides of submaxillary and parotid CA VI thus correlates with the complement of transferases in these glands and suggests differing biological roles for submaxillary and parotid CA VI.
...
PMID:Differential expression of GalNAc-4-sulfotransferase and GalNAc-transferase results in distinct glycoforms of carbonic anhydrase VI in parotid and submaxillary glands. 789 Jul 28
The NH2-terminal fragment of ostrich proopiomelanocortin was isolated and purified following acid/acetone extraction. The amino acid sequence was deduced by automatic Edman degradation of the native as well as CNBr-, tryptic-, and S. aureus protease-derived peptides. Primary structure analysis reveals its close resemblance to other known sequences, especially to amphibian POMC. The usual Trp/Gln-Cys NH2-terminal sequence found in all other homologous sequences, is replaced here by an His-Gly-Pro-Cys sequence. In addition, the
gamma-MSH
sequence, contrary to salmon POMC, is present and contains three substitutions, namely a Ser, an
Asn
, and a Lys residue substituting the normally occurring mammalian Gly, Asp, and Arg residue, respectively. Finally, the molecular weight of this fragment as deduced from ion-spray mass spectrometry and sedimentation equilibrium centrifugation is in close agreement with the proposed structure.
...
PMID:The production of the ostrich NH2-terminal POMC fragment requires cleavage at a unique signal peptidase site. 833 51
Asn
-linked oligosaccharides terminating with the sequence SO4-4GalNAc beta 1,4GlcNAc beta 1,2Man alpha (S4GGnM) are present on the glycoprotein hormones lutropin and thyrotropin, pro-
opiomelanocortin
, and tissue factor pathway inhibitor. The peptide motif ProXaaArg/Lys (PXR/K), which is recognized by a PXR/K-specific GalNAc-transferase, is present in each of these glycoproteins 6-9 residues NH2-terminal to an
Asn
glycosylation site. Both the PXR/K-specific GalNAc-transferase and a GalNAc beta 1,4GlcNAc beta 1,2Man alpha (GGnM)-4-sulfotransferase are required for synthesis of the S4GGnM sequence. Glycoproteins which do not contain the PXR/K motif but bear
Asn
-linked oligosaccharides terminating with GGnM or sialic acid alpha 2,3/6GGnM have also been described, suggesting a distinct GalNAc-transferase may be responsible for their synthesis. We have examined a number of tissues and cultured cell lines for the transfer of sulfate to the trisaccharide acceptor GGnM and transfer of GalNAc to oligosaccharide acceptors on protein which do, human chorionic gonadotropin (hCG), and do not, transferrin (Trf), contain the PXR/K motif. The PXR/K-specific GalNAc-transferase and the GGnM-4-sulfo-transferase are expressed in salivary gland, pituitary, lacrimal gland, kidney, and brain, and in the cell lines AtT-20, 293, SHSY5Y, and alpha T3. In contrast Bowes, EL-4, and B16L6 cell extracts transferred GalNAc to oligosaccharides acceptors on Trf but not on hCG. A number of tissues and cell lines displayed transfer of GalNAc to both hCG and to Trf suggesting that two distinct GalNAc-transferases were present. The GGnM-4-sulfotransferase was expressed in tissues and cell lines which expressed the PXR/K-specific GalNAc-transferase but not in cell lines expressing exclusively the Trf-specific GalNAc-transferase. Thus, the PXR/K-specific GalNAc-transferase and the GGnM-4-sulfotransferase are coordinately expressed in a number of tissues other than pituitary. The Trf-specific GalNAc-transferase may account for the presence of beta 1,4-linked GalNAc on glycoproteins which do not contain the PXR/K motif.
...
PMID:Co-ordinate and restricted expression of the ProXaaArg/Lys-specific GalNAc-transferase and the GalNAc beta 1,4GlcNAc beta 1,2Man alpha-4-sulfotransferase. 834 98
Using reversed-phase HPLC in combination with a radioimmunoassay for ovine
corticotropin
-releasing hormone (CRH), a peptide with CRH-like immunoreactivity was isolated in pure form from an extract of the caudal spinal cord region of the spotted dogfish, Scyliorhinus canicula. The primary structure of the peptide was established as Pro-Ala-Glu-Thr-Pro-
Asn
-Ser-Leu10-Asp-Leu-Thr-Phe-His-Leu-Leu-Arg- Glu-Met-Ile- Glu20-Ile-Ala-Lys-His-Glu-
Asn
-Gln-Gln-Met-Gln30-Ala-Asp-Ser-
Asn
-Arg-Arg-Ile-Met - Asp-Thr40-Ile.NH2. This amino acid sequence shows moderate structural similarity to Catostomus urotensin I (51%) and to human CRH (56%). The data provide, therefore, chemical evidence to support the conclusions of earlier immunohistochemical studies that the diffuse caudal neurosecretory system of elasmobranchs produces a peptide that is immunochemically related to teleost urotensin I peptides. However, the primary structure of urotensin I has been poorly conserved during evolution.
...
PMID:A peptide from the caudal neurosecretory system of the dogfish Scyliorhinus canicula that is structurally related to urotensin I. 853 45
Pro-opiomelanocortin
(POMC) is the precursor of melanocortins (
adrenocorticotropin
: ACTH,
beta-endorphin
, beta-lipotropin:
beta-LPH
,
corticotropin
like intermediate peptide, alpha-, beta- and gamma-melanocyte-stimulating hormone: alpha-, beta- and
gamma-MSH
) some of which act in the brain to reduce food intake and are potential mediators of leptin action. Recently, three different mutations in the POMC gene (POMC) were identified in two unrelated children that lead to early-onset extreme obesity, adrenal insufficiency, and red hair pigmentation. In the present study we systematically screened the coding region of POMC in 96 extremely obese children and adolescents, 60 healthy underweight individuals and 46 patients with anorexia nervosa (AN) and identified several variants. a) A 9 and an 18 base pair insertion (9bp and 18bp: AGC AGC GGC and AGC AGC GGC AGC AGC GGC, respectively, between codon 73 and 74; 1,2). These in-frame variants lead to the insertion of three or six amino acids (Ser-Ser-Gly; Ser-Ser-Gly-Ser-Ser-Gly) carboxy-terminal to
gamma-MSH
. Frequencies of the 9bp insertion allele varied between 3 and 5% among the different study groups (Pearson's chi2 P>0.5). b) Both an out-of-frame 6 bp insertion (within codon 176: GGG CCC) leading to the insertion of two amino acids (Arg-Ala) and a premature stop-codon (G-7316-T: Glu-180-Stop) within the
gamma-LPH
sequence were maternally inherited in an obese female proband. This proband inherited another missense mutation from her father (Glu-188-Gly). c) A missense mutation (G-7016-A; Asp-80-
Asn
) was observed in a single patient with AN who also harboured the 9bp insertion on a paternally derived haplotype. d) The allelic co-occurence of two silent mutations (C-6982-T and C-7285-T) was detected in two obese subjects. e) Two further silent mutations (C-3832-T; C-7111-G) were detected in an underweight and an obese subject, respectively. We conclude that the POMC gene harbors several different polymorphisms and mutations, none of which can readily be associated with the phenotypes under study.
...
PMID:Systematic mutation screening of the pro-opiomelanocortin gene: identification of several genetic variants including three different insertions, one nonsense and two missense point mutations in probands of different weight extremes. 976 93
In order to define which structure of
alpha-melanocyte-stimulating hormone
(MSH) analogues plays a critical role for ligand-receptor interaction and selectivity, we analysed receptor-binding and cAMP-generating activity in Chinese hamster ovary cell lines stably transfected with rMC3R and hMC4R, as well as the NMR structures of chemically synthesized
alpha-MSH
analogues. Compared with [Ahx4]
alpha-MSH
, the linear MTII designated as
alpha-MSH
-ND revealed a preference for the MC4R, whereas its IC50 and EC50 values were comparable to those of MTII reported previously. Truncation of Ahx4 and Asp5 of
alpha-MSH
-ND remarkably decreased the receptor-binding and cAMP-generating activity. Meanwhile, maximum cAMP-generating activity was observed at a higher concentration (10(-5) M) of
alpha-MSH
-ND(6-10), and MC4R preference was changed into MC3R preference. In contrast, [Gln6]
alpha-MSH
-ND(6-10) lost its cAMP-generating activity almost completely, even though it bound to both receptors. Whereas the solution conformation of
alpha-MSH
-ND revealed a stable type I beta-turn structure, [Gln6]
alpha-MSH
-ND(6-10) revealed a tight gamma-turn composed of Gln6-D-Phe7-Arg8. Replacement of the His6 residue of
alpha-MSH
-ND by Gln,
Asn
, Arg or Lys decreased not only the receptor binding, but also the cAMP-generating activity in both the MC3R and the MC4R. The structure of [Gln6]
alpha-MSH
-ND exhibited a stable type I' beta-turn comprising Asp5, Gln6, D-Phe7 and Arg8. [Lys6]
alpha-MSH
-ND showed a greatly reduced binding affinity and cAMP-generating activity with the loss of MC4R selectivity. In NMR studies, [Lys6]
alpha-MSH
-ND also demonstrated a gamma-turn conformation around Lys6-DPhe7-Arg8. From the above results, we conclude that a type I beta-turn conformation comprising the residues Asp5-His6-(D-Phe7)-Arg8 was important for receptor binding and activation, as well as the selectivity of MSH analogues.
...
PMID:Type I beta-turn conformation is important for biological activity of the melanocyte-stimulating hormone analogues. 1049 Dec 1
7B2 is an acidic protein residing in the secretory granules of neuroendocrine cells. Its sequence has been elucidated in many phyla and species. It shows high similarity among mammals. A Pro-Pro-
Asn
-Pro-Cys-Pro polyproline motif is its most conserved feature, being carried by both vertebrate and invertebrate sequences. It is biosynthesized as a precursor protein that is cleaved into an N-terminal fragment and a C-terminal peptide. In neuroendocrine cells, 7B2 functions as a specific chaperone for the proprotein convertase (PC) 2. Through the sequence around its Pro-Pro-
Asn
-Pro-Cys-Pro motif, it binds to an inactive proPC2 and facilitates its transport from the endoplasmic reticulum to later compartments of the secretory pathway where the zymogen is proteolytically matured and activated. Its C-terminal peptide can inhibit PC2 in vitro and may contribute to keep the enzyme transiently inactive in vivo. The PC2-7B2 model defines a new neuroendocrine paradigm whereby proteolytic activation of prohormones and proneuropeptides in the secretory pathway is spatially and temporally regulated by the dynamics of interactions between converting enzymes and their binding proteins. Interestingly, unlike PC2-null mice, which are viable, 7B2-null mutants die early in life from Cushing's disease due to
corticotropin
('ACTH') hypersecretion by the neurointermediate lobe, suggesting a possible involvement of 7B2 in secretory granule formation and in secretion regulation. The mechanism of this regulation is yet to be elucidated. 7B2 has been shown to be a good marker of several neuroendocrine cell dysfunctions in humans. The possibility that anomalies in its structure and expression could be aetiological causes of some of these dysfunctions warrants investigation.
...
PMID:Neuroendocrine secretory protein 7B2: structure, expression and functions. 1143 82
Melanocortin is the downstream mediator of leptin signaling and absence of leptin signaling in ob/ob and db/db mice revealed the enhancement of bone formation through the central regulation. While
alpha-melanocyte-stimulating hormone
(alphaMSH) inhibits the secretion of interleukin-1alpha and tumor necrosis factor-alpha from the inflammatory cells, alphaMSH can also enhance clonal expansion of pro B cells linked to stimulation of osteoclastogenesis. Therefore, we tested the effect of melanocortin on bones. alphaMSH analogues [(6)His]alphaMSH-ND and [(6)
Asn
]alphaMSH-ND were synthesized and the radio-ligand receptor binding- and cyclic AMP generating activity were analyzed in China Hamster Ovary cell line over- expressing melanocortin receptors. The EC(50) of [(6)His]alphaMSH-ND measured from melanocortin-1, 3, 4 and 5 receptors were 0.008 +/- 0.0045, 1.523 +/- 0.707, 0.780 +/- 0.405, and 250.320 +/- 42.234 nM, respectively, and the EC(50) of [(6)
Asn
]alphaMSH-ND were 16.8 +/- 6.94, 271.8 +/- 21.95, 8.0 +/- 1.21, and 1132.5 +/- 635.46 nM, respectively. Four weeks after the subcutaneous injection of the analogues, the body weights in the [(6)His]alphaMSH-ND and the [(6)
Asn
]alphaMSH-ND treated groups (346.0 +/- 20.63 g vs. 350.0 +/- 13.57 g) were lower than that of the vehicle treated group (375.8 +/- 17.31 g, p < 0.05). There was no difference in the total femoral BMD measured by dual x-ray absorptiometry among the three groups. Among the three groups, there were no differences in the total numbers of crystal violet positive- or alkaline phosphatase positive colonies, in the expression of Receptor Activator of Nuclear Factor Kappa-B ligand on the tibia and the total number of multinucleated osteoclast-like cells differentiated from primary cultured bone marrow cells. From the above results, no evidence of bone gain or loss was found after treatment of the alphaMSH analogues peripherally.
...
PMID:The effect of alphaMSH analogues on rat bones. 1220 39
Carboxypeptidase E (CPE) functions as a regulated secretory pathway sorting receptor for several prohormones, including
pro-opiomelanocortin (POMC)
, proenkephalin and proinsulin. The association of CPE with lipid rafts in the trans -Golgi network and secretory granule membranes is necessary for its sorting receptor function. We now provide evidence that a domain within the C-terminal 25 residues of CPE functions as a signal for both raft association and the sorting of CPE to the regulated secretory pathway. A fusion protein containing the extracellular domain of the human interleukin-2 receptor Tac (N-Tac) and the C-terminal 25 amino acids of CPE was transfected into Neuro2A cells. This fusion protein floated in sucrose density gradients, indicating raft association, and co-localized with chromogranin A (CGA), a secretory granule marker. To define further a minimum sequence required for raft association and sorting, deletion mutants of CPE that lacked the C-terminal four or 15 residues (CPE-Delta4 and CPE-Delta15 respectively) were transfected into a clone of CPE-deficient Neuro2A cells. In contrast with full-length CPE, neither CPE-Delta4 nor CPE-Delta15 floated in sucrose density gradients. The sorting of both CPE-Delta4 and CPE-Delta15 to the regulated secretory pathway was impaired, as indicated by significantly increased basal secretion and a lack of response to stimulation. Additionally, there was a significant decrease in the co-localization of mutant CPE immunofluorescence with CGA when compared with full-length CPE. Finally, the sorting of the prohormone POMC to the regulated pathway was impaired in cells transfected with either CPE-Delta4 or CPE-Delta15. We conclude that the sorting of CPE to the regulated secretory pathway in endocrine cells is mediated by lipid rafts, and that the C-terminal four residues of CPE, i.e. Thr(431)-Leu-
Asn
-Phe(434), are required for raft association and sorting.
...
PMID:Sorting of carboxypeptidase E to the regulated secretory pathway requires interaction of its transmembrane domain with lipid rafts. 1240 51
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