Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Increased length of a protein-coding CAG repeat within the androgen receptor gene appears to be the only type of mutation responsible for spino-bulbal muscular atrophy (SBMA or Kennedy disease). We have analysed a large 4-generation SBMA family and found that the mutant allele was unstable upon transmission from parent to child, with a documented variation from 46 to 53 repeats and a tendency to increase in size (7 increases and a single decrease in 17 events), which appeared stronger upon transmission from a male than from a female. Our results suggest also limited somatic instability of the abnormal allele, with observable variation of up to 2-3 repeats. This indicates that the behavior of the CAG repeat is similar to that observed for small premutations in the fragile X syndrome, or small abnormal alleles in myotonic dystrophy, two diseases which are caused by expansion of an unstable trinucleotide repeat.
Hum Mol Genet 1992 Jul
PMID:Moderate instability of the trinucleotide repeat in spino bulbar muscular atrophy. 130 95

Myotonic dystrophy (DM) is associated with the expansion and instability of a trinucleotide (CTG) repeat in a sequence encoding a cAMP-dependent protein kinase. The normal copy number of 5-35 repeats is exceeded in DM patients, with the size of the expansion broadly correlating with the severity of symptoms experienced. In most families reported, the unstable DNA sequence has increased in size on transmission to affected offspring, thereby providing a molecular explanation for the phenomenon of anticipation in DM, i.e. an increase in the severity of symptoms associated with an earlier age at onset of the disease in successive generations of a family. Here we present the first reported case of a family where the transmission of the affected chromosome from father to son is accompanied by a reduction in the size of the triplet expansion, such that it falls within the normal range. As the son remains asymptomatic, this type of molecular event may provide an explanation for the incomplete penetrance of the disease phenotype reported for this disorder. The implications for genetic counselling of DM families and the mechanistic considerations of the trinucleotide instability are discussed.
Hum Mol Genet 1992 Oct
PMID:Unstable DNA may be responsible for the incomplete penetrance of the myotonic dystrophy phenotype. 130 46

The bloodstream form of Trypanosoma brucei contains transcripts of at least four genes showing partial sequence homology to the genes for eucaryotic adenylate and guanylate cyclases (S. Alexandre, P. Paindavoine, P. Tebabi, A. Pays, S. Halleux, M. Steinert, and E. Pays, Mol. Biochem. Parasitol. 43:279-288, 1990). One of these genes, termed ESAG 4, belongs to the polycistronic transcription unit of the variant surface glycoprotein (VSG) gene. Whereas ESAG 4 is transcribed only in the bloodstream form of the parasite, the three other genes, GRESAG 4.1, 4.2, and 4.3, are also expressed in procyclic (insect) forms. These genes differ primarily in a region presumed to encode a large extracellular domain. We show here that ESAG 4-related glycoproteins of about 150 kDa can be found in the trypanosome membrane, that they are detected, by light and electron gold immunocytochemistry, only at the surface of the flagellum, and that the products of at least two of these genes, ESAG 4 and GRESAG 4.1, can complement a Saccharomyces cerevisiae mutant for adenylate cyclase. The recombinant cyclases are associated with the yeast membrane fraction and differ with respect to their activation by calcium: while the GRESAG 4.1 and yeast cyclases are inhibited by calcium, the ESAG 4 cyclase is stimulated. ESAG 4 thus most probably encodes the calcium-activated cyclase that has been found to be expressed only in the bloodstream form of T. brucei (S. Rolin, S. Halleux, J. Van Sande, J. E. Dumont, E. Pays, and M. Steinert. Exp. Parasitol. 71:350-352, 1990). Our data suggest that the trypanosome cyclases are not properly regulated in yeast cells.
Mol Cell Biol 1992 Mar
PMID:A gene from the variant surface glycoprotein expression site encodes one of several transmembrane adenylate cyclases located on the flagellum of Trypanosoma brucei. 154 3

Three different cDNA clones, namely DM1-1, Dah1, and Dah2, encoding hepatic cytochrome P-450, were isolated from a cDNA library in lambda gt11 constructed from liver RNA of polychlorinated biphenyl-treated beagle dogs. DM1-1 was 1857 base pairs (bp) long and encoded a polypeptide of 457 residues. Dah1 was 2394 bp long and contained an entire coding region for 524 amino acid residues. In addition, Dah2 was 1623 bp long and had an open reading frame consisting of 503 amino acid residues, although it lacked the translational initiation codon. Judging from the similarity of the nucleotide and amino acid sequences, forms of cytochrome P-450 encoded by DM1-1, Dah1, and Dah2 were judged to belong to the P450IIC, P450IA1, and P450IA2 subfamilies, respectively. Northern blot analysis of RNA from various tissues, using the specific 3' noncoding regions of Dah1 and Dah2 as probes, indicated that mRNAs for P-450(Dah1) and P-450(Dah2) were not detectable in tissues from untreated dogs, except for P-450(Dah2) in livers. Polychlorinated biphenyl induced both mRNAs in liver, kidney, and lung, especially in the kidney.
Mol Pharmacol 1990 Nov
PMID:Isolation of cDNAs coding for three different forms of liver microsomal cytochrome P-450 from polychlorinated biphenyl-treated beagle dogs. 212 30

31P NMR has been used to observe phosphorus-containing compounds in both perchloric acid and KOH extracts and in whole cell suspensions of Crithidia luciliae. Cells were grown in Bone and Steinert medium, or in a modified RPMI culture medium and harvested after about 72 h in mid- to late log phase. 31P NMR spectra of the perchloric acid extracts indicated that 3-phosphoglycerate, which is normally at low concentrations in most cells, was the dominant phosphorus-containing compound in the sugar phosphate region. 3-Phosphoglycerate is the end product of glycosomal glycolysis and our finding is consistent with previous observations of the failure to detect prior glycolytic intermediates. Other metabolites observed were ATP, ADP, NAD(P)+, phosphoenolpyruvate and low molecular weight polyphosphates (PPn, n less than 20). The presence of high-molecular-weight polyphosphates was established by spectra recorded on extracts obtained through subsequent treatment of the insoluble fraction with KOH. 31P NMR experiments on whole cells indicated that the average main internal pH of cells in late-log growth phase was approx. pH 7.2 +/- 0.1, using the orthophosphate resonance as an indicator. The cells responded to the addition of glucose (final concentration approx. 35 mM) with a decrease in pH, both internal (delta pH = -0.9 (55 min)-1) and external (delta pH = -1.3 (15 min)-1). Polyphosphates and ATP could not be observed in whole cell experiments, although perchloric acid extracts of identically treated cells showed no significant depletion of these compounds.
Mol Biochem Parasitol 1990 Aug
PMID:A 31P nuclear magnetic resonance study of Crithidia luciliae. 223 95

The expression site for the variable surface glycoprotein (VSG) gene AnTat 1.3A of Trypanosoma brucei is 45 kilobases long and encompasses seven expression site-associated genes (ESAGs) (E. Pays, P. Tebabi, A. Pays, H. Coquelet, P. Revelard, D. Salmon, and M. Steinert, Cell 57:835-845, 1989). After UV irradiation, several large transcripts from the putative promoter region were strongly enriched. We report that one such major transcript starts near the poly(A) addition site of the first gene (ESAG 7), spans the intergenic region, and extends to the poly(A) addition site of the second gene (ESAG 6), thus bypassing the normal 3' splice site of the ESAG 6 mRNA. Since this transcript is spliced, we conclude that UV irradiation does not inhibit splicing but stabilizes unstable processing products. This demonstrates that at least some intergenic regions of the VSG gene expression site are continuously transcribed in accordance with a polycistronic transcription model.
Mol Cell Biol 1989 Sep
PMID:Trypanosoma brucei: enrichment by UV of intergenic transcripts from the variable surface glycoprotein gene expression site. 277 75

The trinucleotide expansion mutation causing myotonic dystrophy is in the 3' untranslated region of a protein kinase gene. The molecular mechanisms by which the expanded repeat causes the clinically variable and multisystemic disease, myotonic dystrophy, are not understood. It has been particularly difficult to rationalize the dominant inheritance with the fact that the expansion mutation lies outside of the protein-encoding gene elements, and should not be translated into protein. Here we use muscle biopsies from classical adult-onset myotonic dystrophy patients to study the accumulation of transcripts from both the normal and expanded DM kinase genes in patient muscle, and compare the results to normal and myopathic controls. We found relatively small decreases of DM kinase RNA in the total RNA pool from muscle; however, these reductions were not disease specific. Analysis of poly(A)+ RNA showed dramatic decreases of both the mutant and normal DM kinase RNAs, and these changes were disease-specific. Our findings are consistent with a novel molecular pathogenetic mechanism for myotonic dystrophy: both the normal and expanded DM kinase genes are transcribed in patient muscle, but the abnormal expansion-containing RNA has a dominant effect on RNA metabolism by preventing the accumulation of poly(A)+ RNA. The ability of the expansion mutation to alter accumulation of poly(A)+ RNA in trans suggests that myotonic dystrophy may be the first example of a dominant-negative mutation manifested at the RNA level.
Hum Mol Genet 1995 Apr
PMID:Myotonic dystrophy: evidence for a possible dominant-negative RNA mutation. 754 16

Myotonic dystrophy (DM) is the most common form of inherited neuromuscular disease in adults and is characterized by progressive muscle wasting and myotonia. The mutation responsible for DM has been identified as the amplification of a polymorphic (CTG)n repeat in the 3' untranslated region of a gene encoding a serine/threonine kinase (DMK). We have produced a polyclonal rabbit antibody preparation against a fusion protein encoding the C-terminal amino acids 471-629 of the human DMK gene. This antibody specifically detects products of both full length and truncated human DMK genes expressed in bacteria and in insect cells. On immunoblots, we observed protein species of approximately 74 and 82 kDa in cardiac muscle, skeletal muscle, ependyma and choroid plexus. By immunofluorescence, DMK was found to localize post-synaptically at the neuromuscular junction of skeletal muscle, at intercalated discs of cardiac tissue and at the apical membrane of the ependyma and choroid plexus. We have also detected two to three species (approximately 45-50 kDa) in other regions of the brain. Synaptic localization of DMK in the cerebellum, hippocampus, midbrain and medulla was noted. These results suggest that DMK plays a specialized role in intercellular communication.
Hum Mol Genet 1995 Jun
PMID:Characterization of myotonic dystrophy kinase (DMK) protein in human and rodent muscle and central nervous tissue. 765 60

Myotonic dystrophy (DM) is an autosomal dominant neuromuscular disease. The mutation has been identified as an unstable trinucleotide CTG repeat in a sequence encoding a putative cAMP-dependent protein kinase. The CTG repeat varies in length between affected siblings, and generally increases through generations in parallel with increasing severity of the disease. Congenital myotonic dystrophy, which represents the most severe phenotype, is exclusively maternally inherited. In this report, we show, by Northern blot analysis, that no mutated enlarged transcript is detectable in a 20-week-old DM fetus and in two congenitally affected infants. Furthermore, in skeletal and cardiac muscle of the DM fetus, we observed by RNA analysis, including Northern blot and RT-PCR, an unexpectedly low expression of the paternal wild type allele. Varying degrees of expression of the mutant and/or the normal allele might therefore account for the characteristic features of the congenital form and the extreme variability of the disease.
Hum Mol Genet 1993 Aug
PMID:Myotonic dystrophy: absence of CTG enlarged transcript in congenital forms, and low expression of the normal allele. 769 46

In order to characterize the dynamics of CTG repeat instability in somatic and germline tissue from myotonic dystrophy (DM) males we have used small pool polymerase chain reaction (PCR) in a detailed quantitative analysis of repeat length variation. We demonstrate that the heterogeneous smear of CTG repeats observed in DM patients using standard analyses is comprised of multiple unresolved bands that may be dissected into discrete length alleles derived from single cells using single molecule PCR techniques. Analysis of somatic tissues demonstrates a bias toward increasing allele length and a lower boundary below which variant alleles are rare, consistent with a highly directional expansion pathway in the soma. Two sperm samples show extensive variation and a size increase bias, concordant with the phenomenon of anticipation. In addition, sperm analysis shows that large contractions, including reversions into the normal size range, are restricted to the germline. Detailed analysis of intergenerational 'reductions' paternally transmitted to two offspring suggests that some apparent reductions may be artifacts of somatic expansion in the parent. Our data indicate that in addition to germline variation, substantial somatic expansion can also contribute to the intergenerational differences usually observed in DM.
Hum Mol Genet 1995 Jan
PMID:Somatic mosaicism, germline expansions, germline reversions and intergenerational reductions in myotonic dystrophy males: small pool PCR analyses. 771 20


1 2 3 4 5 6 7 8 9 10 Next >>