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 human alpha(1,3)-fucosyltransferase genes FUT3, FUT5, and FUT6 form a cluster on chromosome 19p13.3. Expression was studied using reverse transcriptase-polymerase chain reaction, rapid amplification of cDNA ends, and Northern analyses. FUT3 and FUT6 were expressed at high levels, while FUT5 expression was lower and restricted to fewer cell types. Alternatively spliced transcripts were identified for FUT3 and FUT6 in kidney, liver, and colon. A 2.37-kilobase pair (kb) FUT3 transcript, detected at high levels in kidney and colon, was absent in liver. FUT6 expression was characterized by a 3.5-kb transcript present in kidney and liver, and a 2.5-kb transcript in colon and liver. Two polyadenylation sites were shown for FUT5, but absence of consensus sequences suggests reduced efficiency for cleavage and polyadenylation. Two polyadenylation sites were also shown for FUT6, with the alternatively spliced downstream signal in tissues expressing high levels of FUT6. In these tissues, additional splicing results in isoforms with catalytic domain deletions. No detectable alpha(1,3)- or alpha(1,4)-fucosyltransferase activity was found in assays of cells transfected with FUT6 isoform cDNAs. Thus, tissue-specific post-transcriptional modifications are associated with expression patterns of FUT3, FUT5, and FUT6.
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PMID:Expression of human chromosome 19p alpha(1,3)-fucosyltransferase genes in normal tissues. Alternative splicing, polyadenylation, and isoforms. 765 30

The Le(x) oligosaccharide is expressed in organ buds progressing in mesenchyma, during human embryogenesis. Myeloid-like alpha3-fucosyltransferases are good candidates to synthesize this oligosaccharide. We investigated by Northern analysis all the alpha3-fucosyltransferase gene transcripts and only FUT4 and FUT9 were detected. The enzymes encoded by the FUT4 and FUT9 genes are the first alpha3-fucosyltransferases strongly expressed during the first two months of embryogenesis. The Northern profile of expression of the embryo FUT4 transcripts is similar in size and sequence to the known FUT4 transcripts of 6 kb, 3 kb, and 2.3 kb, but a new FUT9 transcript of 2501 bp, different from the known mouse (2170 bp) and human (3019 bp) transcripts was cloned. FUT3, FUT5, FUT6, and FUT7 were not detected by Northern blot. The FUT3 and FUT6 transcripts start to appear at this stage, but are only detected by reverse transcriptase-PCR analysis. The expression of FUT5 is weaker than FUT3 and FUT6 and the RT-PCR signal is faint and irregular. FUT7 is not detected at all. Using mRNA from 40- to 65-day-old embryos, we have prepared different hexamer and oligo-dT cDNA libraries and cloned, by rapid amplification cDNA ends-PCR, FUT4 and FUT9 alpha3-fucosyltransferase transcripts. The tissue expression of the embryonic FUT9 transcript is closer to that observed for the mouse (brain), than to the known human (stomach) transcripts. The acceptor specificity and the kinetics of the alpha3-fucosyltransferase encoded by this FUT9 transcript are similar to the FUT4 enzyme, except for the utilization of the lac-di-NAc acceptor which is not efficiently transformed by the FUT9 enzyme. Like FUT4, this embryonic FUT9 is N-ethylmaleimide and heat resistant and the corresponding gene was confirmed to be localized in the chromosome band 6q16. Finally, this FUT9 transcript has a single expressed exon as has been observed for most of the other vertebrate alpha2- and alpha3-fucosyltransferases.
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PMID:FUT4 and FUT9 genes are expressed early in human embryogenesis. 1092 5