Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.5.1.52 (PNGase F)
 1,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A gene encoding the serotonin (5-hydroxytryptamine, 5-HT) receptor (5-HT-hpr) was identified from the sea urchin, Hemicentrotus pulcherrimus. Partial amino acid sequence deduced from the cDNA showed strong similarity to Aplysia californica 5-HT2 receptor. Immunoblotting analysis of this 5-HT-hpr protein (5-HT-hpr) with an antibody raised against a deduced peptide showed two bands. Their relative molecular masses were 69 and 53 kDa, respectively. The larger band alone disappeared after N-glycopeptidase F digestion, indicating the protein was N-glycosylated. Immunolocalization analysis showed that cells expressing the 5-HT-hpr (SRC) first appeared near the tip of the archenteron in 33-h post-fertilization (33 hpf) prism larvae. Their cell number doubled in 2 h, and 5-HT-hpr protein expression increased further without cell proliferation. SRC spread ventrally on the basal surface of the oral ectoderm in 36 hpf prism larvae, and then clockwise on the ventral ectoderm to the posterior region to complete formation of the SRC network in 48 hpf early plutei. The SRC network was comprised of 7 main tracts: 4 spicule system-associated tracts and 3 spicule system-independent tracts. The network extended short fibers to the larval body surface through the ectoderm, implicating a signal transmission system that receives exogenous signal. Double-stain immunohistochemistry with antibodies to primary mesenchyme cells showed that SRC were not stained by the antibody. In embryos deprived of secondary mesenchyme cell (SMC) by microsurgery, the number of SRC decreased considerably. These two data indicate that SRC are SMC descendants, adding a new member to the SMC lineage.
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PMID:The 5-HT receptor cell is a new member of secondary mesenchyme cell descendants and forms a major blastocoelar network in sea urchin larvae. 1511 43

The human serotonin transporter (hSERT) is responsible for reuptake of serotonin (5-HT) from the synaptic cleft and is target for antidepressant medicine. Differential hSERT activity caused by genetic polymorphisms is believed to affect the risk of developing depression and, moreover, to affect the response to antidepressant therapy. The hSERT contains in the second extracellular loop (EL2) two sites for N-linked glycosylation that are critical for functional transporter expression. Here we examine a non-synonymous single nucleotide polymorphism (SNP) in EL2 that gives rise to a potential third glycosylation site due to substitution of a lysine at position 201 with an asparagine (K201N). In agreement with introduction of an additional glycosylation site, western blot analysis showed migration of hSERT K201N corresponding to a higher molecular weight than wild type hSERT upon expression in both HEK293 cells and primary cultures of cortical neurons. An increase in molecular weight was not observed after removal of glycans with peptide N-glycosidase F (PNGase F). Quantitative analysis of western blots indicated significantly increased total transporter expression ( approximately 30%) for hSERT K201N as compared to hSERT in both cell systems. The increase in expression was accompanied by corresponding significant increases in the number of [(3)H]citalopram binding sites and in the V(max) for [(3)H]5-HT uptake. Characterization of mutants carrying all possible combinations of glycosylation sites demonstrated clear correlation between the number of glycosylation sites and the level of transporter activity, and showed that K201N could substitute for either one of the two original glycosylation sites.
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PMID:A single nucleotide polymorphism in the human serotonin transporter introduces a new site for N-linked glycosylation. 1950 Jun 2

JC virus (JCV) is a human polyomavirus and the causative agent of the fatal demyelinating disease progressive multifocal leukoencephalopathy (PML). JCV infection of host cells is dependent on interactions with cell surface asparagine (N)-linked sialic acids and the serotonin 5-hydroxytryptamine(2A) receptor (5-HT(2A)R). The 5-HT(2A)R contains five potential N-linked glycosylation sites on the extracellular N terminus. Glycosylation of other serotonin receptors is essential for expression, ligand binding, and receptor function. Also, glycosylation of cellular receptors has been reported to be important for JCV infection. Therefore, we hypothesized that the 5-HT(2A)R N-linked glycosylation sites are required for JCV infection. Treatment of 5-HT(2A)R-expressing cells with tunicamycin, an inhibitor of N-linked glycosylation, reduced JCV infection. Individual mutation of each of the five N-linked glycosylation sites did not affect the capacity of 5-HT(2A)R to support JCV infection and did not alter the cell surface expression of the receptor. However, mutation of all five N-linked glycosylation sites simultaneously reduced the capacity of 5-HT(2A)R to support infection and altered the cell surface expression. Similarly, tunicamycin treatment reduced the cell surface expression of 5-HT(2A)R. Mutation of all five N-linked glycosylation sites or tunicamycin treatment of cells expressing wild-type 5-HT(2A)R resulted in an altered electrophoretic mobility profile of the receptor. Treatment of cells with PNGase F, to remove N-linked oligosaccharides from the cell surface, did not affect JCV infection in 5-HT(2A)R-expressing cells. These data affirm the importance of 5-HT(2A)R as a JCV receptor and demonstrate that the sialic acid component of the receptor is not directly linked to 5-HT(2A)R.
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PMID:Role of N-linked glycosylation of the 5-HT2A receptor in JC virus infection. 2066 Jan 94