 Joanne F. Berson

Joanne F. Berson led a 2001 study of how Pmel17 helps form premelanosomes, the developing compartments in which melanin is deposited. The researchers followed processing and localization of the protein, then expressed it in nonpigmented cells. Expression alone initiated characteristic internal striations within multivesicular bodies.^[ref]

That reconstruction addressed causation more directly than finding Pmel17 beside existing pigment: a normally nonpigmented cell acquired part of the specialized internal architecture after the protein was introduced. It established a role in compartment construction without implying that one protein recreates every step of pigment production.