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Resolution of translation start site for the human K ell glycoprotein
Author(s) -
Blacken Grady R.,
Zimring James C.,
Fu Xiaoyun
Publication year - 2013
Publication title -
transfusion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.045
H-Index - 132
eISSN - 1537-2995
pISSN - 0041-1132
DOI - 10.1111/trf.12267
Subject(s) - glycoprotein , furin , complementary dna , n terminus , microbiology and biotechnology , methionine , biochemistry , trypsin , biology , peptide sequence , chemistry , amino acid , gene , enzyme
Background The human K ell blood group system currently contains 35 antigens determined by allelic polymorphisms in the K ell glycoprotein, a single‐pass T ype II transmembrane protein. The K ell glycoprotein was initially cloned through screening of a cDNA library; however, direct amino acid sequencing of most of the K ell glycoprotein has not been reported. The N ‐terminus of the K ell glycoprotein contains two potential translational start sites, which result in differences in the cytoplasmic tail. Study Design and Methods Protein extracts were isolated from human red blood cell membranes and were digested with trypsin. The resulting peptides were subjected to liquid chromatography–tandem mass spectrometry, allowing resolution of peptides from the N ‐terminus of the K ell glycoprotein. Results Peptides were isolated and sequenced that correspond to the upstream methionine start site predicted by the full cDNA sequence. No evidence of internal translation initiation at M ethionine 20 was detected. Conclusions These findings identify the translational start site and define the full cytoplasmic tail of the human K ell glycoprotein.