Human epidermis is a novel site of phospholipase B expression.
Phospholipase B (PLB) is an enzyme that displays both phospholipase A(2) and lysophospholipase activities. Analysis of human epidermis homogenates indicated the presence of a 97 kDa PLB protein, as well as a phospholipase A(2) activity, both being enriched in the soluble fraction. Immunolabelling and in situ hybridization experiments showed that this enzyme is expressed in the different layers of epidermis with an accumulation at the dermo-epidermis junction. RT-PCR data indicated that PLB is specifically expressed in natural and reconstructed epidermis. By 3'-RACE-PCR and screening of human genome databases, we obtained a 3600 bp cDNA coding for human PLB highly homologous to already described intestinal brush border PLBs. These data led us to conclude that the soluble PLB corresponds to a proteolytic cleavage of the membrane anchored protein. Altogether, our results provide the first characterization of human PLB which should play an important role in epidermal barrier function.
Maury
Eric
E
Institut de recherche Pierre Fabre, CERPER/Hôtel Dieu Saint Jacques, F31052 Toulouse, France.
Prévost
Marie Claude
MC
Nauze
Michel
M
Redoulès
Daniel
D
Tarroux
Roger
R
Charvéron
Marie
M
Salles
Jean Pierre
JP
Perret
Bertrand
B
Chap
Hugues
H
Gassama-Diagne
Ama
A
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D015342:DNA Probes; D004817:Epidermis / Q000201:enzymology*; D005230:Fatty Acids, Nonesterified / Q000096:biosynthesis; D006801:Humans; D017403:In Situ Hybridization; D008245:Lysophospholipase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000201:enzymology
D015342:DNA Probes; D005230:Fatty Acids, Nonesterified; D008245:Lysophospholipase