Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biochemical characterization of a serotonin (5HT) receptor and the cloning of a dopamine (DA) receptor in the central nervous system (CNS) of the leech, Theromyzon tessulatum, is presented. Additionally, DA and 5HT binding sites were examined in the CNS by Scatchard analysis which showed a single, relatively high-affinity binding site with a Kd 1.1 nM and a Bmax 126+18 fmol/mg protein for [3H]DA and a Kd 2.1 nM and a Bmax 225 fmol/mg protein for [3H]5HT. The first 88 amino acids of the 5HT receptor, isolated by a 5HT-affinity column followed by anion exchange chromatography and C3 reverse-phase HPLC exhibited a 43% sequence homology with Lymnaea stagnalis 5HT-receptor. The isolated DA receptor revealed a single protein of 45 kDa with an anti-D1-R in Western blot. The first 80 N-terminal amino acid residues and a trypsin digested fragment of 31 residues were obtained, and based on these sequencing data, a molecular biology strategy using reverse transcriptase-polymerase chain reaction, was developed. An amplified 1-kb segment was obtained. The complete deduced sequence of 416 amino acid residues exhibited about 30.6% sequence homology with the vertebrate D1 receptor family. Moreover, we further demonstrate that the leech 5HT and DA receptors also exhibit 30% sequence identity with each other, explaining their pharmacological cross-reactivity. Finally, anti-D1-R immunocytochemistry revealed positive structures in the peripheral and central nervous system, e.g., neurons, sensory fibers and immune cells. This is the first biochemical and molecular characterization of a DA receptor in leeches.
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PMID:Putative leech dopamine1-like receptor molecular characterization: sequence homologies between dopamine and serotonin leech CNS receptors explain pharmacological cross-reactivities. 968 82

The leech Myzobdella lugubris is widespread in the Lake Erie Watershed, especially Lake St. Clair. However, its role in pathogen transmission is not fully understood. In this same watershed, several widespread fish mortalities associated with the Viral Hemorrhagic Septicemia virus (VHSV) were recorded. Viral Hemorrhagic Septicemia is an emerging disease in the Great Lakes Basin that is deadly to the fish population, yet little is known about its mode of transmission. To assess the potential role of M. lugubris in VHSV transmission, leeches were collected from Lake St. Clair and Lake Erie and pooled into samples of five. Cell culture and reverse transcriptase polymerase chain reaction (RT-PCR) were used to determine the presence of the virus and its identity. Results showed that 57 of the 91 pooled leech samples were positive by cell culture for VHSV and 66 of the 91 pooled leech samples were positive by RT-PCR for the VHSV. Two representative virus isolates were sequenced for further genetic confirmation and genotype classification. VHSV detected within M. lugubris was homologous to the Great Lakes strain of VHSV genotype IVb. This is the first record of the VHSV being detected from within a leech, specifically M. lugubris, and suggests the potential of M. lugubris being involved in VHSV transmission.
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PMID:Detection of Viral Hemorrhagic Septicemia virus (VHSV) from the leech Myzobdella lugubris Leidy, 1851. 1978 52