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

Here we report the primary structure of potato cytochrome c1, a nuclear-encoded subunit of complex III. Using heterologous antibodies directed against cytochrome c1 from yeast two types of clones were isolated from an expression library, suggesting that at least two different genes are present and expressed in the genome. Northern blot analysis reveals that slightly varying levels of cytochrome c1 transcripts are present in all potato tissues analysed. A 1304 bp insert of one of the cDNA clones (pC13II) encodes the entire 320 amino acids of the precursor protein corresponding to a molecular weight of 35.2 kDa. As revealed by direct amino acid sequence determination of the cytochrome c1 protein another cDNA clone (pC18I) encodes the major form of cytochrome c1 present in potato tuber mitochondria. Western blots of subfractionated potato mitochondria show that the mature protein present in the membrane fraction is smaller than the pC13II encoded protein synthesized in Escherichia coli. The transient presequence of the protein is 77 amino acids long and has a bipartite polarity profile characteristic of presequences involved in targeting to the intermembrane space of fungal mitochondria. It consists of a positively charged NH2-terminal part which resembles "matrix targeting domains" and an adjacent hydrophobic region showing sequence similarities to "intramitochondrial sorting domains". The amino-terminal region of potato cytochrome c1 is the first presequence of a plant protein of the mitochondrial intermembrane space to be determined and may be useful in the study of intramitochondrial sorting in plants.
Mol Gen Genet 1992 Jan
PMID:Cytochrome c1 from potato: a protein with a presequence for targeting to the mitochondrial intermembrane space. 131 May 21

In the mouse mammary tumor virus (MMTV)-infected mouse T-lymphoma cell line W7MG1, glucocorticoid hormone regulates two aspects of MMTV gene expression: hormone stimulates MMTV gene transcription and increases the ratio of mature envelope proteins to envelope precursor protein produced. To separate these two effects and determine the mechanism by which hormone regulates the conversion of the envelope precursor Pr74 to the mature cleaved products gp52 and gp33, we constructed expression vectors in which the envelope gene is constitutively transcribed. Surprisingly, the envelope precursor protein Pr74 encoded by two independently isolated, allelic envelope genes behaved differently. Pr74-P (encoded by the ENV/P gene) was processed efficiently to the mature products gp52 and gp33, independently of the level of expression, hormonal induction of cellular genes, or the presence of other MMTV proteins. In contrast, under the same conditions, Pr74-N (encoded by the ENV/N gene) was not processed further despite being relatively stable. In sucrose gradient analyses, Pr74-P sedimented as monomers, whereas Pr74-N was found in high mol wt aggregates of heterogeneous size. Coimmunoprecipitation analysis determined that Pr74-N associated with BiP, whereas Pr74-P did not. This is indicative of improper folding of Pr74-N in the endoplasmic reticulum.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Endocrinol 1992 Mar
PMID:Two different genes coding for processable and nonprocessable forms of a viral envelope protein can account for the apparent hormonal stimulation of protein processing in W7MG1 lymphoma cells. 131 43

Although resident peritoneal cells from amyloidotic mice (amyloidotic peritoneal cells) are capable of processing the precursor protein of secondary amyloidosis, serum amyloid A (SAA) to amyloid fibrils, the peritoneum is a rare site for amyloid deposition. This is considered to be due to a deficiency of SAA in the peritoneum. To increase the supply of SAA to the peritoneum, ascitic fluid containing about the same protein constituents as in the serum was induced in mice. Amyloidotic peritoneal cells were packed in a microchamber which was shielded with filter membranes, and cultured in ascitic fluid supplemented with additional inflammatory factors. On the 7th day, Congo red-positive structures which showed green birefringence under polarized light were found inside and occasionally outside the chamber. By anti-AA or -SAA immunostaining, amyloid deposits and the cell surfaces of macrophages were positive. Immunologic depletion of T- and B-lymphocytes from the amyloidotic peritoneal cells did not adversely effect the amyloid formation in microchambers. These results suggest that either ascitic fluid containing sufficient amounts of SAA, or peritoneal macrophages with a high amyloid enhancing factor (AEF) activity are indispensable for AA amyloid fibrillogenesis in the peritoneum.
Virchows Arch B Cell Pathol Incl Mol Pathol 1992
PMID:Intraperitoneal amyloid formation by amyloid enhancing factor--rich macrophages in ascitic fluid. 135 97

We have isolated an ovine insulin-like growth factor-binding protein-2 (IGFBP-2) cDNA from an adult sheep cDNA library, to determine the structure of ovine IGFBP-2 and to examine the pattern of IGFBP-2 gene expression in adult sheep tissues. This cDNA had 81, 96 and 87% identity with the rat, bovine and human sequences respectively. The deduced amino acid sequence of the ovine IGFBP-2 showed 86, 95 and 85% homology with the rat, bovine and human peptide sequences respectively. The ovine IGFBP-2 cDNA encoded a precursor protein of 317 amino acids which comprised a 33 residue hydrophobic leader sequence and a 284 residue, 30.9 kDa, mature peptide. The 18 cysteine residues, which are a characteristic feature of IGFBPs, were conserved. Also, an Arg-Gly-Asp (RGD) sequence near the C terminus was present. A single transcript of approximately 1.5 kb was expressed in abundance in selected tissues of an adult sheep, namely liver, kidney, adrenal, pituitary and choroid plexus. Southern blot analysis of ovine genomic DNA with the cDNA probe demonstrated that IGFBP-2 is encoded by a single gene. These findings indicate that the ovine IGFBP-2 protein is similar to that in other species and that, in the adult, the mRNA is expressed only in selected tissues.
J Mol Endocrinol 1992 Aug
PMID:The characterization and expression of ovine insulin-like growth factor-binding protein-2. 138 Nov 82

Saposins are a group of small glycoproteins derived from a single precursor protein, prosaposin. Each of the four saposins are involved in lysosomal hydrolysis of various sphingolipids. Our recent investigations have shown that saposins accumulate in tissues of several lysosomal storage diseases patients, including those with Tay-Sachs disease and Gaucher disease. To obtain insight into the mechanism of accumulation and its pathological role, the subcellular distribution of saposins in brain from Tay-Sachs disease and in spleen of Gaucher disease were compared with that of GM2 ganglioside and glucocerebroside, respectively. In both Tay-Sachs brain and Gaucher spleen, saposins were found predominantly in light-density fractions while most of the GM2 ganglioside and glucocerebroside, respectively, were found in heavy-density fractions. These studies indicate that saposins that accumulate in these pathological tissues are not tightly associated with GM2 ganglioside or glucocerebroside.
J Mol Neurosci 1992
PMID:Distribution of saposins (sphingolipid activator proteins) in tissues of lysosomal storage disease patients. 138 98

A genomic DNA clone encoding an aspartic proteinase inhibitor of potato was isolated from a lambda EMBL3 phage library using the aspartic proteinase inhibitor cDNA as a hybridization probe. The gene has all characteristic sequences normally found in eucaryotic genes. Typical CAAT and TATA box sequences were found in the 5'-upstream region. In this part are also two putative regulatory AGGA box sequences located. In the genomic sequence there are no intron sequences interrupting the coding region. An open reading frame of the gene encodes a precursor protein of 217 amino acids which shows high percent identity with the aspartic proteinase inhibitor cDNA.
Plant Mol Biol 1992 Oct
PMID:Isolation and sequence analysis of the genomic DNA fragment encoding an aspartic proteinase inhibitor homologue from potato (Solanum tuberosum L.). 139 74

Previously we have shown that nuclear extracts from mouse cells contain a heterogeneous group of polypeptides (p65, p80, p90, p100) which form distinct DNA-protein complexes on the 18 base-pair sequence element (termed Sal-box), which constitutes the murine rDNA transcription termination signal. These distinct proteins mediate cessation of RNA polymerase I (pol I) transcription elongation and release of the nascent RNA chains, indicating that they function as termination factor(s). Here, we report the biochemical analysis of the pol I-specific transcription termination factor TTFI. We show that the heterogeneity of TTFI is due to limited proteolysis of a larger, 130 kDa precursor protein (p130). The DNA-binding activity of p130 is strongly reduced as compared to the proteolytic derivatives, indicating that the DNA-binding domain is repressed within the full-length molecule. We have used limited proteolysis to purify and functionally characterize a TTFI core polypeptide (p50) which still specifically binds to the Sal-box target sequence and directs rDNA transcription termination. The equilibrium constant of purified p50 to bind specifically to DNA is 9 x 10(9) M-1. Additionally, we demonstrate that TTFI binds to DNA as a monomer and that binding induces DNA bending. This observation suggests that not only specific DNA-protein and protein-protein interactions but also conformational alterations of DNA may play a role in the termination process.
J Mol Biol 1992 Oct 05
PMID:Limited proteolysis unmasks specific DNA-binding of the murine RNA polymerase I-specific transcription termination factor TTFI. 140 80

Neuromedin U (NmU), a peptide originally isolated from porcine spinal cord, is known for its ability to stimulate uterine smooth muscle contraction and to cause selective vasoconstriction. It was subsequently isolated from a number of species. Among the species studied, the five amino acids at the C-terminus of the peptide are totally conserved, suggesting that this region is of major importance. We have cloned and sequenced the cDNA encoding the rat NmU precursor protein using the anchor polymerase chain reaction technique. Sequence analysis revealed that NmU is synthesized as a 174-amino acid precursor. Like the precursors of most other small regulatory peptides, it has a hydrophobic signal peptide and a number of paired dibasic amino acids, which may serve as signals for enzymatic cleavage, to release NmU and a series of other peptides. These predicted flanking peptides of NmU show no significant homology with entries in the protein databases searched, and the cDNA likewise shows no homology with entries in the GenBank database. Northern blot analysis using total RNA extracted from different rat tissues shows high levels of NmU mRNA in the ileum, thyroid, and anterior pituitary. Southern blot analysis of rat genomic DNA demonstrates that NmU is a single copy gene.
Mol Endocrinol 1992 Oct
PMID:Characterization of complementary DNA encoding the rat neuromedin U precursor. 144 9

We have isolated a gene encoding a previously unreported class of trypanosomatid cysteine proteinase (CP) from the protozoan parasite Leishmania mexicana. The single-copy gene (lmcpa) [corrected]. has several unusual features that distinguish it from CP genes cloned from the related species Trypanosoma brucei and Trypanosoma cruzi. These include a shorter C-terminal extension of only 10 amino acids and a three-amino-acid insertion, GlyValMet, close to the predicted N-terminus of the mature protein. Northern blot analysis showed that the gene is expressed in all life-cycle stages but at higher levels in the amastigote stage in the mammal and in stationary phase promastigote cultures which contain the infective metacyclic form of the parasite. A precursor protein of 38 kDa was detected in amastigotes and stationary phase promastigotes with antisera specific to the LmCPa pro-region, but was barely detectable in early log-phase promastigotes. Anti-central domain antisera recognized the 38 kDa precursor and 24 and 27 kDa proteins. The major CPs of L. mexicana amastigotes, previously designated types A, B and C, were not detected with the antisera, suggesting that the gene codes for a previously uncharacterized CP in L. mexicana. The 24 kDa protein detected by the antiserum has no activity towards gelatin but apparently hydrolyses the peptide substrate BzPheValArgAMC. The relative levels of the 24 and 27 kDa proteins vary between the different life-cycle stages. The results indicate that expression of this CP is regulated at both the RNA and protein level.
Mol Microbiol 1992 Jul
PMID:A developmentally regulated cysteine proteinase gene of Leishmania mexicana. 150 41

The angiotensinogen gene encodes the precursor protein for the potent vasoconstrictor angiotensin II. Although the gene is expressed in several tissues, the liver is the major source of circulating protein. In previous in-vivo studies we have found that a mini-gene containing 750 bp of 5'-flanking sequence is transcribed in a manner which largely parallels the expression of the endogenous gene. In this report, we characterized conserved elements in the promoter region, in order to determine their role in the transcription of the angiotensinogen gene. Constructs fused to the chloramphenicol acetyl transferase (CAT) reporter gene were transfected into hepatocarcinoma Hep G2 cells as well as into nonhepatic cell lines. We found that 5'-deletion mutant constructs, containing sequences from +25 to -90 bp and -321 to -750 bp, were each able to activate transcription. These constructs contain the TATA box and core promoter sequences, including an Sp1-binding site, and two glucocorticoid responsive elements respectively. In the non-hepatic cell lines, HeLa and Jeg-3, we found that the constructs were transcribed at a much lower rate when compared with the expression of a plasmid containing the Rous sarcoma virus long terminal repeat fused to the CAT gene. Constructs which included sequence 5' to -244 were oestrogen inducible. An element which is conserved between rodent and human angiotensinogen promoters is contained within a sequence which is oestrogen responsive, while another binds the liver-enriched transcriptional activator hepatocyte nuclear factor 1. However, the role of this transactivator in the transcription of angiotensinogen remains uncertain.
J Mol Endocrinol 1992 Aug
PMID:The function of conserved elements in the promoter of the mouse angiotensinogen gene. 151 23


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