L-Phenylalanine Transport in Saccharomyces cerevisiae: Participation of GAP1, BAP2, and AGP1

Table 5

Specificity of phenylalanine uptake in gap1 cells grown in MP and MA media^a.

Unlabelled amino acid added	Percentage inhibition
	Y294Δgap1		Y294Δbap2Δgap1		Y294Δagp1Δgap1
	MP	MA	MP	MA	MP	MA
Leucine	39	45	34	34	4	51
Tryptophan	17	18	18	25	4	23
Asparagine	45	29	48	35	4	0
Proline	ND	8	ND	13	ND	12
DL-TFL^b	ND	30	ND	3	ND	37
𝛽-2TA^c	ND	43	ND	31	ND	55

aHigh-affinity phenylalanine uptake was measured at 4 min with L-[¹⁴C]-phenylalanine 20 𝜇M and the unlabelled amino acids were added at 200 𝜇M. Control values in the absence of competitor in strains Y294Δgap1, Y294Δbap2Δgap1, and Y294Δagp1Δgap1 grown in MP medium were 1.89, 1.63, and 0.44 and for cells grown in MA medium were 1.59, 0.98, and 1.09 𝜇mol g⁻¹, respectively.
bDL-trifluoroleucine.
^c𝛽-2-thienylalanine.