Molecular cloning and characterization of a novel putative carboxylesterase, present in human intestine and liver.
A full-length cDNA coding for a putative intestinal carboxylesterase (iCE) was isolated from a human small intestine cDNA library. The cDNA has an open reading frame of 559 amino acids with up to 65% homology to other carboxylesterases of different mammalian species. The deduced amino-acid sequence contains many structural features, that are highly conserved among all carboxylesterase isoenzymes, like the serine esterase active site, an ER-retention signal and one Asn-Xxx-Thr site for N-linked carbohydrate addition. Northern blot analysis revealed that the corresponding mRNA is 3.4-3.6 kb in size and is preferentially expressed in human intestine with a weak signal also in liver. Analysis of cells from the gastrointestinal tract unveiled site-specific, transcriptional regulation of iCE, with higher expression in small intestine and lower expression in colon and rectum. The high expression in small intestine is attributable to a higher expression in jejunum compared to duodenum and ileum.
Schwer
H
H
Institute for Clinical Chemistry and Laboratory Medicine, University of Regensburg, Germany.
Langmann
T
T
Daig
R
R
Becker
A
A
Aslanidis
C
C
Schmitz
G
G
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D043182:Carboxylesterase; D002265:Carboxylic Ester Hydrolases / Q000235:genetics*; D003001:Cloning, Molecular; D018076:DNA, Complementary; D006801:Humans; D007421:Intestine, Small / Q000201:enzymology*; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D012333:RNA, Messenger; D002265:Carboxylic Ester Hydrolases; D043182:Carboxylesterase