The ectodomain shedding of CD30 is specifically regulated by peptide motifs in its cysteine-rich domains 2 and 5.
Tumor necrosis factor (TNF)-alpha converting enzyme (TACE) is responsible for the ectodomain release of various membrane proteins by proteolytic cleavage in close proximity to the cell membrane. Despite the wide spectrum of possible substrates, selective cleavage can be achieved by substrate cross-linking. To explore the underlying mechanism, we studied the TACE-mediated shedding of CD30. Whereas the constitutive release of the soluble ectodomain of CD30 (sCD30) from the lymphoma cell line Karpas 299 was enhanced by most anti-CD30 antibodies, it was inhibited by antibodies Ber-H2 and Ki-4. On the basis of the recognized epitopes, shedding seemed to depend on the availability of the cysteine-rich domains (CRD) 2 and 5 of the CD30 ectodomain. CRD2 and 5 have almost identical amino acid sequences and are localized distant from the TACE-targeted cleavage site. Soluble CD30, the product of this enzyme reaction, did not inhibit, but on the contrary, it stimulated CD30 shedding in a CRD2/5-dependent manner. This process could also be induced by CRD2/5-derived peptides but not by a CRD1-derived control peptide. This example of a product-activation was CD30 selective since other TACE substrates such as TNFR1 or TNF-alpha were not affected. These data suggest that CD30 shedding is stimulated by an elevated local availability of CRD2 or 5, possibly by forming a docking station for the releasing enzyme through substrate aggregation.
Hansen
Hinrich P
HP
Department of Internal Medicine I, University Hospital Cologne, LFI, Ebene 4, Room 703, Joseph-Stelzmann-Str. 9, 50924 Cologne, Germany. h.hansen@uni-koeln.de
Recke
Andreas
A
Reineke
Ulrich
U
Von Tresckow
Bastian
B
Borchmann
Peter
P
Von Strandmann
Elke Pogge
EP
Lange
Hans
H
Lemke
Hilmar
H
Engert
Andreas
A
D051722:ADAM Proteins; D000072198:ADAM17 Protein; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D019556:COS Cells; D045744:Cell Line, Tumor / Q000378:metabolism; D002522:Chlorocebus aethiops; D003545:Cysteine / Q000737:chemistry; D000939:Epitopes / Q000276:immunology; D006689:Hodgkin Disease / Q000473:pathology; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D017730:Ki-1 Antigen / Q000737:chemistry* / Q000276:immunology / Q000378:metabolism; D008228:Lymphoma, Non-Hodgkin / Q000473:pathology; D008666:Metalloendopeptidases / Q000378:metabolism; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D010446:Peptide Fragments / Q000494:pharmacology; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D017384:Sequence Deletion; D017386:Sequence Homology, Amino Acid; D012995:Solubility; D013329:Structure-Activity Relationship; D013379:Substrate Specificity; D014162:Transfection
D000911:Antibodies, Monoclonal; D000939:Epitopes; D007140:Immunoglobulin Fab Fragments; D017730:Ki-1 Antigen; D009363:Neoplasm Proteins; D010446:Peptide Fragments; D051722:ADAM Proteins; D008666:Metalloendopeptidases; D000072198:ADAM17 Protein; C000606462:ADAM17 protein, human; D003545:Cysteine