Discovery of a novel splice variant of Fcar (CD89) unravels sequence segments necessary for efficient secretion: A story of bad signal peptides and good ones that nevertheless do not make it.

ABSTRACT: The IgA receptor, Fcar (CD89) consists of 5 sequence segments: 2 segments (S1, S2) forming the potential signal peptide, 2 extracellular EC domains that include the IgA binding site, and the transmembrane and cytoplasmic tail (TM/C) region. Numerous Fcar splice variants have been reported with various combinations of the sequence segments mentioned above. Here, we report a novel splice variant termed variant APD isolated from a healthy volunteer that lacks only the IgA-binding EC1 domain. Despite possessing the complete signal peptide S1+S2, the variant APD is only found in the intracellular space whereas the wild-type variant 1 is efficiently secreted and variant 4 leaks to the extracellular space. Further mutational experiments involving signal peptide replacements, cleavage site modific

SUBMITTER: Lua WH 

PROVIDER: S-EPMC5351921 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature