. 2008 Dec 5;8(2):147–160. doi: 10.1128/EC.00229-08

TABLE 3.

Phenotypes caused by amino acid exchanges in Mep2p

Mutation	Mep2p level^a^,^g	Growth phenotype^b	Ammonium transport phenotype^c^,^g	Filament formation phenotype^d
Y122A	Reduced	Slightly reduced	Reduced	Slightly reduced
Y126A	Reduced	Strongly reduced	Strongly reduced	Defective^e
W165A	Slightly reduced	Normal	Normal^f	Normal
W167A	Reduced	Normal	Slightly reduced	Abolished
D180L	Absent	No growth	NT	Abolished
D180N	Absent	No growth	NT	Abolished
H188A	Absent	No growth	NT	Abolished
S243A	Slightly reduced	Normal	Normal	Normal
F239A	Reduced	No growth	NT	Abolished
H342A	Absent	No growth	NT	Abolished
D419N	NT	Normal	NT	Normal^h
E420G	NT	Normal	NT	Normal^h
M422E	NT	Normal	NT	Abolished
L423A	NT	Normal	NT	Normal^h
T425V	NT	Normal	NT	Normal^h
L427E	NT	Normal	NT	Abolished
A428D	NT	Normal	NT	Strongly reduced
Y433F	NT	Normal	NT	Normal^h

Determined by fluorescence-activated cell sorter analysis of strains expressing GFP-tagged Mep2p (Fig. 3).

Growth in liquid SLAD medium and/or on agar plates containing limiting ammonium concentrations (Fig. 1, 2, 4, 5, and 7).

Determined by ammonium removal assay (Fig. 5A).

Filament formation on agar plates containing 100 μM ammonium, proline, or urea (Fig. 1, 4, 6, and 7).

Normal filament formation on plates containing 100 μM proline, but no filament formation on plates containing other limiting nitrogen sources (Fig. 4 and 6).

Data not shown.

NT, not tested.

Hyperfilamentation because of the ΔC435 truncation.