The mouse Kell blood group gene (Kel): cDNA sequence, genomic organization, expression, and enzymatic function

Area of Science:

• Biochemistry
• Genetics
• Immunology

Background:

• The Kell blood group system is vital in transfusion medicine due to antigen polymorphism and potential for severe transfusion reactions.
• Maternal Kell alloimmunization can cause fetal and neonatal anemia.
• Kell is a membrane glycoprotein linked to XK, absence of which causes McLeod syndrome.

Purpose of the Study:

• To determine the cDNA sequence, gene organization, protein expression, and enzymatic function of the mouse Kell homologue.
• To compare mouse and human Kell proteins and genes.

Main Methods:

• cDNA sequencing
• Gene organization analysis
• Northern blot analysis for gene expression
• Western blot analysis for protein characterization

Main Results:

• Mouse and human Kell cDNA showed 80% nucleotide and 74% amino acid identity.
• Mouse Kell has more N-linked carbohydrate side chains and an additional extracellular cysteine compared to human Kell.
• The mouse Kell gene (Kel) is organized into 19 exons and located on Chromosome 6.
• High Kel expression was observed in spleen, with weaker levels in testis and heart.
• Mouse Kell glycoprotein has an apparent molecular weight of 110,000 (80,000 after deglycosylation) and exhibits endothelin-3-converting enzyme activity, similar to human Kell.

Conclusions:

• The mouse Kell homologue shares significant sequence and functional similarities with human Kell.
• This mouse model provides a valuable tool for studying the Kell blood group system, transfusion reactions, and McLeod syndrome.