Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.4.24.55 (PTR)
 433 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cyclo(PheN2-Tyr-D-Trp-Lys-Val-PheC3)-Thr-NH2 (PTR 3046), a backbone-cyclic somatostatin analogue, was synthesized by solid-phase methodology. The binding characteristics of PTR 3046 to the different somatostatin receptors, expressed in CHO cells, indicate high selectivity to the SSTR5 receptor. PTR 3046 is highly stable against enzymatic degradation as determined in vitro by incubation with rat renal homogenate and human serum. The biological activity of PTR 3046 in vivo was determined in rats. PTR 3046 inhibits bombesin- and caerulein-induced amylase and lipase release from the pancreas without inhibiting growth hormone or glucagon release. The major conformation of PTR 3046 in CD3OH, as determined by NMR, is defined by a type II' beta-turn at D-Trp-Lys and a cis amide bond at Val-PheC3.
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PMID:A backbone-cyclic, receptor 5-selective somatostatin analogue: synthesis, bioactivity, and nuclear magnetic resonance conformational analysis. 952 66

We have isolated and characterized the Saccharomyces cerevisiae PTR3 gene by functional complementation of a mutant deficient for amino acid-inducible peptide transport. PTR3 is predicted to encode a protein of 678 amino acids that exhibits no similarity to any other protein in the database. Deletion of the PTR3 open reading frame pleiotropically reduced the sensitivity to toxic peptides and amino acid analogues. Initial rates of radiolabelled dipeptide uptake demonstrated that elimination of PTR3 resulted in the loss of amino acid-induced levels of peptide transport. PTR3 was required for amino acid-induced expression of PTR2, the gene encoding the dipeptide/tripeptide transport protein, but was not necessary for nitrogen catabolite repression of peptide import or PTR2 expression. It was determined that PTR3 also modulates expression of BAP2, the gene encoding the branched-amino acid permease. Furthermore, we present genetic evidence that suggests that PTR3 functions within a novel regulatory pathway that facilitates amino acid induction of the PTR system.
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PMID:PTR3, a novel gene mediating amino acid-inducible regulation of peptide transport in Saccharomyces cerevisiae. 970 22

Almost a quarter of a century ago, the banding patterns of human and other higher primate chromosomes were compared, creating a barrage of speculation. Consequently, a number of approaches have been used to understand human descent. Chromosome modifications are believed to be important in the origin of species, and pericentric inversions account for the majority of evolutionary chromosomal alterations seen in Hominoidea. A comparative mapping fluorescence in situ hybridization technique, using locus-specific DNA probes as phylogenotic markers, was used to decipher the pericentric inversions of human chromosomes 11 and 12. Human-derived (Homo sapiens, HSA) DNA probes for GLI, HST and INT2 protooncogenes were used to identify their homologous locations in the chromosomes of chimpanzee (Pan troglodytes, PTR), gorilla (Gorilla gorilla, GGO) and orangutan (Pongo pygmaeus, PPY). The INT2 and HST loci mapping results confirm the earlier putative claim that a pericentric inversion took place in HSA chromosome 11 and its equivalent PTR and GGO chromosomes. In addition, these data provide additional information regarding the orangutan's position on the evolutionary tree of Pongidae and Hominidae. GLI mapping reveals that a pericentric inversion occurred in the HSA chromosome 12 equivalent in PTR and GGO, but was not seen in HSA or PPY. These pericentric inversions in PTR and GGO may have occurred at a period when both PTR and GGO had branched off from the Hominoidae trunk. The use of loci-specific probes to decipher pericentric inversions has proved to be a formidable approach in characterizing chromosome rearrangements and providing further evidence on human descent.
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PMID:Evolutionary divergence of the oncogenes GLI, HST and INT2. 972 Mar

We have cloned and characterized the opt1 gene of Drosophila melanogaster. This gene encodes a protein with significant similarity to the PTR family of oligopeptide transporters. The OPT1 protein is localized to the apical epithelial membrane domains of the midgut, rectum, and female reproductive tract. The opt1 message is maternally loaded into developing oocytes, and OPT1 is found in the alpha-yolk spheres of the developing embryo. It is also found throughout the neuropil of the central nervous system, with elevated expression within the alpha- and beta-lobes of the mushroom bodies. Transport activity was examined in HeLa cells transiently expressing OPT1. This protein is a high-affinity transporter of alanylalanine; the approximate Km constant is 48.8 microM for this substrate. OPT1 dipeptide transport activity is proton dependent. The ability of selected beta-lactams to inhibit alanylalanine transport suggests that OPT1 has a broad specificity in amino acid side chains and has a substrate requirement for an alpha-amino group. Together these data suggest an important role for OPT1 in regulating amino acid availability.
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PMID:The opt1 gene of Drosophila melanogaster encodes a proton-dependent dipeptide transporter. 973 Sep 71

Effects of saphenous nerve stimulation (SNS) on the Hering-Breuer expiratory-promoting reflex evoked by a positive tracheal pressure (PTR; 5 cmH2O) and on the diaphragmatic EMG (EMG(DI)), inspiratory (TI) and expiratory (TE) time, were studied in 16 urethane-anesthetized (1.2-1.6 g/kg, i.p.) spontaneously breathing 2-week-old rabbits. Positive P(TR) applied at the end of T(I) increased the subsequent TE to 255+/-29% (+/-S.E.; P < 0.0001) of control. SNS (1 sec train, 2 msec pulse, 6 Hz) applied at the onset of TE, shortened this TE by 42+/-3% (P < 0.0001). When SNS preceded positive PTR or positive PTR preceded SNS, the TE increased to 163+/-20 and 184+/-21% of control, respectively. These responses were not different, and smaller than that provoked by the PTR test alone (P < 0.003 and 0.05, respectively). The results show that in newborns somatic afferent stimulation attenuates the vagally mediated respiratory inhibition, whether immediately before or during the vagal stimulation.
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PMID:Interaction between somatic and vagal afferent inputs in control of ventilation in 2-week-old rabbits. 1042 Oct 31

Relative phylogenetic divergence of the members of the Pongidae family has been based on genetic evidence. The recent isolation of subtelomeric probes specific for human (HSA) chromosomes 1q, 11p, 13q, and 16q has prompted us to cross-hybridize these to the chromosomes of the chimpanzee (Pan troglodytes, PTR), gorilla (Gorilla gorilla, GGO), and orangutan (Pongo pygmaeus, PPY) to search for their equivalent locations in the great apes. Hybridization signals to the 1q subtelomeric DNA sequence probe were observed at the termini of human (HSA) 1q, PTR 1q, GGO 1q, PPY 1q, while the fluorescent signals to the 11p subtelomeric DNA sequence probe were observed at the termini of HSA 11p, PTR 9p, GGO 9p, and PPY 8p. Fluorescent signals to the 13q subtelomeric DNA sequence probe were observed at the termini of HSA 13q, PTR 14q, GGO 14q, and PPY 14q, and positive signals to the 16p subtelomeric DNA sequence probe were observed at the termini of HSA 16q, PTR 18q, GGO 17q, and PPY 19q. These findings apparently suggest sequence homology of these DNA families in the ape chromosomes. Obviously, analogous subtelomeric sequences exist in apes' chromosomes that apparently have been conserved through the course of differentiation of the hominoid species.
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PMID:Localization of subtelomeric sequences of human chromosomes 1q, 11p, 13q, and 16q in the higher primates. 1048 91

The aim of this work was to correlate anatomic and urodynamic measures with function following bladder neck surgery. Eighty-seven women who underwent bladder neck surgery at two tertiary academic medical centers in the southeastern U.S. were studied in this prospective outcomes analysis. Preoperative and 6-week and 6-month postoperative status was assessed with urodynamic testing, physical examination, and condition-specific quality of life instruments. Correlations of dynamic urethral obstruction (quantified by pressure transmission ratio, PTR, determinations) and urethral support (quantified by urethral axis measurements) with functional status were determined. At 6 weeks, 50% of the subjects with inadequate dynamic obstruction (PTR < 90%) had genuine stress incontinence (GSI) compared to 5% of those with PTR >/= 90% (P = .00002). Of those with excessive obstruction (PTR > 110%), 32% had detrusor instability (DI) and 47% had emptying phase dysfunction (EPD) compared to 6% and 24%, respectively, of those with PTR </= 110% (P = .006 and P = .04). At 6 months, subjects with excessive obstruction were more likely to have EPD than other subjects (75% vs. 27%, P = .001). Those with optimal dynamic obstruction (PTR >/= 90% but </= 110%) were more likely to have normal function (no GSI, no DI, and no EPD) than those with higher or lower PTRs (59% vs. 34%, P = .04). Urethral axis measurements did not correlate with functional status at either follow-up session. The magnitude of dynamic urethral obstruction is related to function after bladder neck surgery. Excessive obstruction is associated with DI and EPD, inadequate obstruction with GSI, and optimal obstruction with normal function. Neurourol. Urodynam. 18:629-637, 1999.
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PMID:Understanding lower urinary tract function in women soon after bladder neck surgery. Continence Program for Women Research Group. 1052 11

Elucidating how rice (Oryza sativa) takes up nitrate at the molecular level could help improve the low recovery rate (<50%) of nitrogen fertilizer in rice paddies. As a first step toward that goal, we have cloned a nitrate transporter gene from rice called OsNRT1. OsNRT1 is a new member of a growing transporter family called PTR, which consists not only of nitrate transporters from higher plants that are homologs of the Arabidopsis CHL1 (AtNRT1) protein, but also peptide transporters from a wide variety of genera including animals, plants, fungi, and bacteria. However, despite the fact that OsNRT1 shares a higher degree of sequence identity with the two peptide transporters from plants (approximately 50%) than with the nitrate transporters (approximately 40%) of the PTR family, no peptide transport activity was observed when OsNRT1 was expressed in either Xenopus oocytes or yeast. Furthermore, contrasting the dual-affinity nitrate transport activity of CHL1, OsNRT1 displayed only low-affinity nitrate transport activity in Xenopus oocytes, with a K(m) value of approximately 9 mM. Northern-blot and in situ hybridization analysis indicated that OsNRT1 is constitutively expressed in the most external layer of the root, epidermis and root hair. These data strongly indicate that OsNRT1 encodes a constitutive component of a low-affinity nitrate uptake system for rice.
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PMID:Cloning and functional characterization of a constitutively expressed nitrate transporter gene, OsNRT1, from rice. 1067 31

We have generated a panel of 55 somatic cell hybrids retaining fragments of human chromosome 4. Each hybrid has been characterized cytogenetically by FISH and molecularly by 37 STSs, evenly spaced along the chromosome. The panel can be exploited to map subregionally DNA sequences on chromosome 4 and to generate partial chromosome paints useful in the characterization of chromosomal rearrangements involving this chromosome. Furthermore, a panel of 84 YACs mapping on chromosome 4 has been characterized by FISH. A subset of this panel is recognized by STSs used in the somatic cell hybrid characterization. In this way a correlation between the genetic and the physical maps can be established. These resources have been used to investigate the conservation of the phylogenetic chromosome IV in great apes. The results indicate that all the pericentric inversions that differentiate chromosome IV in these species are distinct and that one of the breakpoints frequently lies very close to the centromere. In 4 instances, the YAC containing the breakpoint was identified. The breakpoint in IVq of PTR and MMU lies in the same YAC, suggesting that this breakpoint has been utilized twice in the evolutionary history of this chromosome.
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PMID:Molecular cytogenetic resources for chromosome 4 and comparative analysis of phylogenetic chromosome IV in great apes. 1070 78

Karyotypic homologies in relation to human chromosome 14 and 9 were studied through comparative mapping of the immunoglobulin C epsilon genes in higher primates by fluorescence in situ hybridization (FISH) technique. The C epsilon genes will be suitable probes for the analysis of evolutionary rearrangements due to that the multiple recombinational events such as gene duplications and deletions have occurred repeatedly in the immunoglobulin CH gene family (IGH@) during the course of primate evolution. IGH@ locating on the terminal region of human chromosome 14 (HSA14), at band HSA14q32.33, has generated multiple pseudogenes and among subclasses of IGH@ the C epsilon genes have shown most dynamic changes with generating both truncated type (C epsilon 2) and processed type (C epsilon 3) pseudogenes. In this study, chromosomal homologies and rearrangements on HSA14 (C epsilon 1) and HSA9 (C epsilon 3) in relation to the evolutionary genesis of their primate homologous chromosomes in speciation were investigated by comparative mapping with FISH and chromosome painting (ZOO-FISH) techniques. Comparative mapping of the C epsilon 1 gene at HSA14q32.33 was carried out in seven species of nonhuman primates: common chimpanzee (PTR), pygmy chimpanzee (PPA), gorilla (GGO), orangutan (PPY), white-handed gibbon (HLA), agile gibbon (HAG), and Japanese macaque (MFU). The C epsilon 1 gene was assigned to the telomeric region of HSA14 homologues in each species, namely, PTR15q32, PPA15q32, GGO18q16, PPY15q32, HLA17qter, HAG17qter, and MFU7q29, respectively. These results suggested that HSA14 has high degree of syntenic organization with its primate homologues confirmed by ZOO-FISH. Concerning HSA9, comparative mapping of the C epsilon 3 gene at HSA9p24.2-->p24.1 was performed. The mapped positions indicated the HSA9 homologous regions detected by ZOO-FISH in each species, namely, PTR11q34, PPA11q34, GGO13q22, PPY13q16, HLA8qter, HAG8qter, and MFU14q22, respectively, suggesting that several dynamic chromosomal rearrangements including at least twice pericentric inversions have occurred during the course of hominoid evolution. The comparison of syntenic groups and painting results has provided a hypothesis of the evolutionary genesis of HSA9 and its homologues with defined breakpoints on the present chromosomes. Likewise, studies on karyotype evolution will be promoted by combining comparative mapping with ZOO-FISH that can more clearly define the chromosomal rearrangements among species.
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PMID:Studies on karyotype evolution in higher primates in relation to human chromosome 14 and 9 by comparative mapping of immunoglobulin C epsilon genes with fluorescence in situ hybridization. 1085 38


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