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Title
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Two novel human pancreatic lipase related proteins, hPLRP1 and hPLRP2. Differences in colipase dependence and in lipase activity.
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Authors
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T.Giller,
P.Buchwald,
D.Blum-Kaelin,
W.Hunziker.
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Ref.
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J Biol Chem, 1992,
267,
16509-16516.
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PubMed id
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Abstract
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We have isolated cDNAs coding for two novel human pancreatic lipase
(hPL)-related human proteins, referred to as hPL-related proteins 1 and 2
(hPLRP1 and hPLRP2) and for hPL. The two novel proteins show an amino acid
sequence identity to hPL of 68 and 65% for hPLRP1 and 2, respectively. All three
proteins are secreted into the medium after transfection of COS cells with the
corresponding cDNAs. The size of the three expressed proteins is similar and
ranges between 45 and 50 kDa. The expressed hPLRP2 shows a lipolytic activity
that is, however, in contrast to that of hPL only marginally dependent on the
presence of colipase, whereas hPLRP1 shows no activity in this assay. A Northern
analysis of normal human pancreas mRNA shows that the expression levels of
hPLRP1 and hPLRP2 are about 4-fold and 24-fold lower, respectively, than that of
hPL. hPLRP2 is, additionally, most closely related to a lipase reported to be
expressed in mouse T-cells. A comparison of the sequences of the three proteins
with sequences described as pancreatic lipases of other animal species shows
three subfamilies of closer kinship. This suggests that the two novel proteins
also exist in other species and that some of the sequences reported to be
pancreatic lipase might more likely be the orthologues of hPLRP1 or hPLRP2 in
those species.
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