FIGURE 6.

Mechanistic hypothesis by which FNTA regulates ApoA-I secretion. FNTA post-translationally adds a farnesyl group (F) to the –SH of the cysteine near the end of proteins, typically targeting the modified protein to membranes based on the hydrophobicity of the farnesyl group. CENPF is a farnesylated protein, and the siRNA directed toward CENPF caused a 1.98× increase in ApoA-I secretion in our study. We hypothesize that this initial farnesylation event is important for downstream events necessary for appropriate ApoA-I secretion. Through indirect (dotted arrows) and direct (solid arrows) interactions with downstream proteins known to be involved in vesicle transport and exocytosis, FNTA directs downstream events that lead to ApoA-I secretion.