Identification of Possible Testosterone Transporters

The discovery of the MCT8 transporter, which carries thyroid hormones into cells, changed our understanding of how hormones work. It showed that hormones need special transporters to enter cells — they can’t just slip through the membrane on their own, as was once thought.

Based on this idea, we propose that there are also specific transporters for testosterone. If these transporters don’t function properly, this could explain why some people with a 46,XY genetic background (genetically male) show resistance to androgen actions, even though their hormone levels and hormone receptors appear normal.

Our project aims to identify such testosterone transporter genes using three complementary approaches:

1. Developing a sensitive test that measures how quickly and effectively testosterone enters cells and activates them.

2. Screening the genomes of more than 120 patients with disorders of sex development (DSD) to find harmful changes in possible transporter genes.

3. Testing these candidate genes in the lab to confirm whether they really transport testosterone.

Finding testosterone transporters could help explain previously mysterious DSD cases, deepen our understanding of testosterone biology, and open up new treatment options for affected individuals.