StarD7 is found in the cytosol and associated with the mitochondrion.[5] When overproduced in the cell, mitochondrial levels of phosphatidylcholine rise.[5] High levels of the protein are found in tumor cells compared to normal cells, suggesting a role in cell proliferation.[6]
There are two forms of StarD7: StarD7-I and StarD7-II. The former is 295 amino acids long. StarD7-I possesses an additional 75 amino acids at its amino-terminus, which form a signaling sequence that targets it to the outer membrane of the mitochondrion.[5]
StarD7 contains a StAR-related transfer domain (START), from which it derives its name. Moreover, the protein is a member of the predominantly phosphatidylcholine transporter subfamily of START proteins, the StarD2 subfamily. It shares 25% sequence identity with StarD2.[5]
