Jose received recognition for his research from the American Medical Student Association. In the summer of 1997, he joined the Cell Biology and Metabolism Branch of the National Institute of Child Health and Human Development, where, under the guidance of mentor Juan Bonifacino, Ph.D., he mastered several fairly sophisticated molecular biology procedures. The goal of the project, which he continued to work on under the sponsorship of the UGSP when he returned to NIH in the summer of 1998, was to determine whether the mutant protein that is associated with disease is directed in the wrong destination in cells, a targeting error that might account for many of the symptoms of Hermansky-Pudlak syndrome. Hermansky-Pudlak syndrome is a fairly rare autosomal recessive disease that occurs most frequently in isolated populations. People who have the disease usually die before they reach 50 years of age and suffer from albinism, a tendency to bleed, and lysosomal storage disease.
Researchers believe that the syndrome is caused by a frame shift mutation.
As a result, the protein that is synthesized from the mutant gene contains errors at one end of its 750-amino acid sequence. Because this end of the normal protein is important for determining its destination in a cell, researchers hypothesized that the mutant protein might be targeted to the wrong location. To find out where the normal protein is located in a cell, he performed a series of procedures. He put the normal gene, called a wild-type gene, into a vector containing an epitope tag and inserted the gene construct into HeLa cells in culture. Thus, when the transfected HeLa cells that expressed the protein also expressed the tag, which Jose labeled with a fluorescent antibody.