Expression of lactase-phlorizin hydrolase in sheep is regulated at the RNA level.
Biochem J
; 302 ( Pt 3): 929-35, 1994 Sep 15.
Article
em En
| MEDLINE
| ID: mdl-7945222
ABSTRACT
Lactase-phlorizin hydrolase (LPH) is expressed on the intestinal brush border and is responsible for the hydrolysis of lactose, the chief sugar in mammalian milk. The enzyme activity of LPH peaks soon after birth in most mammals and declines to much lower levels before adolescence. The molecular basis of this pattern of expression has not been clearly established. We have measured relative amounts of LPH mRNA in intestine from sheep with ages across a developmental spectrum, including third trimester fetal lambs, newborn lambs and adult sheep. LPH mRNA levels in the jejunum decline approximately 50-fold between infancy and adulthood, in parallel with the reduction in both lactase specific activity and immunologically reactive lactase protein expression in sheep jejunum. LPH mRNA is present in high concentration in the duodenum of newborn lambs, but steadily declines by day 34 and is dramatically reduced in adults. Because the changes in LPH mRNA, protein, and enzymic activity are generally parallel, we conclude that the developmental regulation of LPH in sheep is probably mediated primarily at the mRNA level.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
RNA Mensageiro
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Regulação Enzimológica da Expressão Gênica
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Lactase-Florizina Hidrolase
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Mucosa Intestinal
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Intestino Delgado
Limite:
Animals
/
Humans
Idioma:
En
Revista:
Biochem J
Ano de publicação:
1994
Tipo de documento:
Article