Yet this knowledge could be "a matter of life and death," says University of Vermont biologist Bryan Ballif.
While blood transfusion problems due to Langereis and Junior blood types are rare worldwide, several ethnic populations are at risk, Ballif notes. "More than 50,000 Japanese are thought to be Junior negative and may encounter blood transfusion problems or mother-fetus incompatibility," he writes.
But the molecular basis of these two blood types has remained a mystery — until now.
In the February issue of Nature Genetics, Ballif and his colleagues report on their discovery of two proteins on red blood cells responsible for these lesser-known blood types.
Ballif identified the two molecules as specialized transport proteins named ABCB6 and ABCG2.
"Only 30 proteins have previously been identified as responsible for a basic blood type," Ballif notes, "but the count now reaches 32."
The last new blood group proteins to be discovered were nearly a decade ago, Ballif says, "so it’s pretty remarkable to have two identified this year."
Both of the newly identified proteins are also associated with anticancer drug resistance, so the findings may also have implications for improved treatment of breast and other cancers.
As part of the international effort, Ballif, assistant professor in the biology department, used a mass spectrometer at UVM funded by the Vermont Genetics Network. With this machine, he analyzed proteins purified by his longtime collaborator, Lionel Arnaud at the French National Institute for Blood Transfusion in Paris, France.
Ballif and Arnaud, in turn, relied on antibodies to Langereis and Junior blood antigens developed by Yoshihiko Tani at the Japanese Red Cross Osaka Blood Center and Toru Miyasaki at the Japanese Red Cross Hokkaido Blood Center.