Table 1. Expression and secretion of individual GAUTs in HEK293 cells.

The number after the Δ represents the amino acid residue truncation site at which each GAUT construct was truncated to remove its putative TMD or to provide the in vivo cleavage site (GAUT1) prior to insertion into the pGEn2-DEST vector for expression in HEK293 cells. Synthesis in the cells and secretion into the medium of each GAUT protein was monitored by fluorescence of the N-terminal domain GFP tag. Values are total gross fluorescence units and represent the average ± SEM of the designated GAUT protein expression from at least two independent 20 mL HEK293 cell cultures.

GAUT	Cells & Medium Fluorescence	Medium Fluorescence
1Δ42†	379 ± 144	105 ± 2
1Δ167†	639 ± 34	366 ± 31
3Δ28	164 ± 9	69 ± 3
4Δ29	27 ± 5	18 ± 1
5Δ31	129 ± 42	50 ± 11
6Δ31	32 ± 2	19 ± 0
7Δ43	204 ± 60	59 ± 20
8Δ43	30 ± 5	19 ± 0
9Δ50	242 ± 112	35 ± 8
10Δ39†	953 ± 111	372 ± 3
11Δ39†	1128 ± 187	795 ± 82
12Δ59	302 ± 100	46 ± 6
13Δ61†	718 ± 52	245 ± 23
14Δ61†	715 ± 67	296 ± 30
15Δ70	380 ± 47	35 ± 3

^†These constructs were selected for purification from the HEK293 medium