Complementary DNA

About: Complementary DNA is a research topic. Over the lifetime, 55301 publications have been published within this topic receiving 2752650 citations. The topic is also known as: cDNA & DNA, Complementary.

Numerous candidate plasticity-related genes revealed by differential cDNA cloning

Abstract: PLASTICITY is a property of the nervous system that allows it to modify its response to an altered input. This capacity for change suggests that there are molecular mechanisms in neurons that can couple stimuli to long-term alterations in phenotype1–3. Neuronal excitation elicits rapid transcriptional activation of several immediate–early genes4, for example c-fos, c-jun and zif268. Many immediate–early genes encode transcription factors that control expression of downstream genes whose products are believed to bring about long-term plastic changes3,4. Here we use a highly sensitive differential complementary DNA cloning procedure to identify genes that may participate in long-term plasticity. We cloned 52 cDNAs of genes induced by the glutamate analogue kainate in the hippocampus dentate gyrus. The number of these candidate plasticity-related genes (CPGs) is estimated to be 500–1,000. One of the cloned CPGs (16C8), encoding a protease inhibitor, is induced by a stimulus producing long-term potentiation and during dentate gyrus development; a second, cpgl, is dependent on activation of the NMDA (N-methyl-D-aspartate) receptor for induction and encodes a new small, dentate-gyrus-specific protein. Seventeen of the cloned CPGs encode known proteins, including six suggesting that strong neuronal activation leads to de novo synthesis of vesicular and other synaptic components.

Characterization of a cDNA encoding a novel DNA-binding protein, SPF1, that recognizes SP8 sequences in the 5′ upstream regions of genes coding for sporamin and β-amylase from sweet potato

Abstract: We isolated a cDNA encoding a DNA-binding protein, SPF1, of sweet potato that binds to the SP8a (ACTGTGTA) and SP8b (TACTATT) sequences present in the 5′ upstream regions of three different genes coding for sporamin and β-amylase of tuberous roots. SPF1 comprises 549 amino acids and is enriched in both basic and acidic residues. The amino acid sequence of SPF1 shows no significant homology to any known protein sequences, suggesting that it may represent a new class of DNA-binding protein. Binding studies with 35S-labeled SPF1, synthesized in vitro, and synthetic DNA fragments indicated that, although SPF1 binds to both the SP8a and SP8b sequences, it binds much more strongly to SP8a than to SP8b. SPF1 bound to the SP8a sequence as a monomer. The DNA-binding domain of SPF1 was localized within the C-terminal half of this protein, and a 162-amino acid fragment of SPF1 (Met310-Arg472) showed DNA-binding activity with no change in target sequence specificity. This fragment contains a region enriched in basic amino acids adjacent to a highly acidic stretch. A sequence which is highly homologous to a 40-amino acid sequence in the basic region of the DNA-binding domain is duplicated in the N-terminal part of SPF1. The gene coding for SPF1 is present in one or a few copies per haploid genome and the SPF1 mRNA was detected in leaves, stems and tuberous roots of the sweet potato, in addition to petioles. The level of SPF1 mRNA in the petioles decreased when leaf-petiole cuttings were treated with sucrose to induce accumulation of sporamin and β-amylase mRNAs.