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P D Beremand

Publications and source records attributed to P D Beremand.

6 recordsLinked to original sources

Gene expression in the developing mouse retina by EST sequencing and microarray analysis.

Retinal development occurs in mice between embryonic day E11.5 and post-natal day P8 as uncommitted neuroblasts assume retinal cell fates. The genetic pathways regulating retinal development are being identified but little is understood about the global networks that link these pathways together or the complexity of the expressed gene set required to form the retina. At E14.5, the retina contains mostly uncommitted neuroblasts and newly differentiated neurons. Here we report a sequence analysis of an E14.5 retinal cDNA library. To date, we have archived 15 268 ESTs and have annotated 9035, which represent 5288 genes. The fraction of singly occurring ESTs as a function of total EST accrual suggests that the total number of expressed genes in the library could approach 27 000. The 9035 ESTs were categorized by their known or putative functions. Representation of the genes involved in eye development was significantly higher in the retinal clone set compared with the NIA mouse 15K cDNA clone set. Screening with a microarray containing 864 cDNA clones using wild-type and brn-3b (-/-) retinal cDNA probes revealed a potential regulatory linkage between the transcription factor Brn-3b and expression of GAP-43, a protein associated with axon growth. The retinal EST database will be a valuable platform for gene expression profiling and a new source for gene discovery.

Animals↗

Isolation and nucleotide sequence of a sesquiterpene cyclase gene from the trichothecene-producing fungus Fusarium sporotrichioides.

The trichodiene synthase gene (Tox5) has been isolated from the fungus Fusarium sporotrichioides, and its nucleotide (nt) sequence determined. A lambda gt11 library of F. sporotrichioides DNA was screened with antiserum against trichodiene synthase (TS). DNA fragments were isolated which encode a portion of the Tox5 gene. In subsequent screening of the library we employed one of these DNAs as a probe and identified several recombinant phage containing the entire Tox5 gene. The gene consists of a 1182-nt open reading frame (ORF) which contains a 60-nt intron and specifies a Mr 43,999 protein. The deduced amino acid sequence of the ORF was identical to sequences determined for several CNBr peptides from purified TS. Southern and Northern analyses indicated that the Tox5 gene is present in a single copy and is transcribed into an mRNA of about 1450 nt. Upstream from the start codon, 'TATA'-like sequences and a short repeated sequence resembling the 'CCAAT' box were observed. The primary structure described for TS is the first such report for a member of the terpene cyclase group of enzymes.

Amino Acid Sequence↗

Purification and characterization of recombinant spinach acyl carrier protein I expressed in Escherichia coli.

Expression of plant acyl carrier protein (ACP) in Escherichia coli at levels above that of constitutive E. coli ACP does not appear to substantially alter bacterial growth or fatty acid metabolism. The plant ACP expressed in E. coli contains pantetheine and approximately 50% is present in vivo as acyl-ACP. We have purified and characterized the recombinant spinach ACP-I. NH2-terminal amino acid sequencing indicated identity to authentic spinach ACP-I, and there was no evidence for terminal methionine or formylmethionine. Recombinant ACP-I was found to completely cross-react immunologically with polyclonal antibody raised to spinach ACP-I. Recombinant ACP-I was a poor substrate for E. coli fatty acid synthesis. In contrast, Brassica napus fatty acid synthetase gave similar reaction rates with both recombinant and E. coli ACP. Similarly, malonyl-coenzyme A:acyl carrier protein transacylase isolated from E. coli was only poorly able to utilize the recombinant ACP-I while the same enzyme from B. napus reacted equally well with either E. coli ACP or recombinant ACP-I. E. coli acyl-ACP synthetase showed a higher reaction rate for recombinant ACP-I than for E. coli ACP. Expression of spinach ACP-I in E. coli provides, for the first time, plant ACP in large quantities and should aid in both structural analysis of this protein and in investigations of the many ACP-dependent reactions of plant lipid metabolism.

Acyl Carrier Protein↗

Synthesis, cloning, and expression in Escherichia coli of a spinach acyl carrier protein-I gene.

A synthetic gene of 268 bp encoding the 82 amino acid spinach acyl carrier protein (ACP)-I was constructed based on the known amino acid sequence. Two gene fragments, one encoding the amino-terminal portion and the other the carboxy-terminal portion of the protein, were assembled from synthetic oligonucleotides and inserted into the phage M13mp19. These partial gene constructions were joined and inserted into the plasmid pTZ19R. DNA sequencing confirmed the accuracy of the constructions. The synthetic gene was then subcloned into the Escherichia coli expression vector pKK233-2, under the control of the trc promoter. Western blot analysis and radioimmunoassay indicated that E. coli cells carrying this plasmid produced up to 6 mg/liter of a protein which was immunologically cross-reactive and similar in electrophoretic mobility to authentic spinach acyl carrier protein. The bacterial cells were able to attach the phosphopantetheine prosthetic group to the synthetic plant gene product allowing it to be acylated in vitro by acyl-ACP synthetase.

Acyl Carrier Protein↗

Mutational analysis of serine-glycine biosynthesis in Rhodopseudomonas capsulata.

Rhodopseudomonas capsulata possesses the enzymes of both the "phosphorylated" and the "non-phosphorylated" pathways of serine biosynthesis. Certain mutants with lesions in the phosphorylated pathway are serine-glycine auxotrophs, though they still produce enzymes of the non-phosphorylated sequence. These results indicate that the phosphorylated pathway is essential for the synthesis of serine and glycine in R. capsulata under the condtions tested.

Carbohydrate Dehydrogenases↗