The sequential cleavage of membrane anchored pro-EGF requires a membrane serine protease other than kallikrein in rat kidney.
Epidermal growth factor (EGF) is present in kidney membranes as an integral type I precursor protein, enzymatically processed to release immunoreactive materials in urine or incubation medium. The aim of this work was the elucidation of both the anchor of the serine protease activity that processes pro-EGF, and the determination of the steps of the enzymatic processing. Quantification of EGF containing molecules by RIA following gel filtration analysis demonstrated that the membrane precursor is first shed from the kidney membrane principally into a 170-kDa soluble precursor. This entire ectodomain is further processed into a 70-kDa precursor and finally into the mature 5.9 kDa urinary EGF. These species correspond to the ones found in urines. Both shedding and maturation events are clearly realized by membrane anchored serine protease activity, which remains active in detergent. By use of wild-type and knockout mice urines, we found that tissue kallikrein (TK) was not involved in the regulation of this processing.
Le Gall
Sylvain M
SM
Institut de Biochimie et Biophysique Moléculaire et Cellulaire CNRS UMR 8619, Université Paris XI Bât 430, 91405 Orsay Cedex, France.
Meneton
Pierre
P
Mauduit
Philippe
P
Dreux
Catherine
C
D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism*; D002850:Chromatography, Gel; D004815:Epidermal Growth Factor / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D007610:Kallikreins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D007668:Kidney / Q000201:enzymology / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D011498:Protein Precursors / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D051381:Rats; D012697:Serine Endopeptidases / Q000378:metabolism*
D010446:Peptide Fragments; D011498:Protein Precursors; C042652:epidermal growth factor precursor; D004815:Epidermal Growth Factor; D007610:Kallikreins; D012697:Serine Endopeptidases