Premium
Thyroglobulin type‐I‐like domains in invariant chain fusion proteins mediate resistance to cathepsin L digestion
Author(s) -
Hitzel Christoph,
Kanzler Holger,
König Angelika,
Kummer Markus P.,
Brix Klaudia,
Herzog Volker,
Koch Norbert
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)02189-x
Subject(s) - thyroglobulin , cysteine , cathepsin l , cathepsin , chemistry , biochemistry , fusion protein , microbiology and biotechnology , cathepsin a , gene isoform , cathepsin d , cathepsin h , biology , genetics , gene , enzyme , recombinant dna , antibody
The MHCII associated invariant chain isoform Ii41 shows homology to a repeat in thyroglobulin (TgR). We show that the Ii31 isoform, which lacks the TgR‐like domain, is sensitive to cathepsin L treatment whereas Ii41 displays substantial resistance. The TgR‐like sequence of Ii41 was exchanged for thyroglobulin type‐IA and ‐IB repeats, that contain six or four cysteine residues. Resistance to cathepsin L digestion was maintained upon substitution of the Ii41 TgR for homologous sequences from TgR type‐IA. Mutation of a conserved cysteine in the TgR domain of an Ii fusion protein strongly reduced resistance to cathepsin L digestion.