9.C.10 The Liver Nicotinic/Nicotinamide Transporter (LNNT) Family Said et al. (2007) have reported the uptake of nicotinic acid (niacin) in human liver cells by an energy dependent, Na⁺-independent, carrier-mediated process (K_m= 1nM). The process was inhibited by nicotinate and nicotinamide but not by unrelated organic anions. Inhibitors of Ca²⁺-calmodulin inhibited uptake. The carrier was not identified. The probable transport reaction is: niacin (out) niacin (in)
References:
Said, H.M., S.M. Nabokina, K. Balamurugan, Z.M. Mohammed, C. Urbina, and M.L. Kashyap. (2007). Mechanism of nicotinic acid transport in human liver cells: experiments with HepG2 cells and primary hepatocytes. Am. J. Physiol. Cell Physiol. 293: C1773-1778.
Examples:
TC#	Name	Organismal Type	Example