Table 1.

Levels of 10A1 MLV and A-MLV entry supported by human PiT2 and derived truncation mutants^a.

Constructb	No. (%) of cells infectedc
	A-MLV			10A1 MLV
	Expt 1d	Expt 2d	Expt 4	Expt 1d	Expt 2d	Expt 3d	Expt 4	Expt 5
PiT2 (pOJ74)	100 ±22	100 ± 8	100 ±12	100 ± 5	100 ± 8	100 ± 9	100 ±11	100 ± 9
PiT2ΔL183-V483	25 ± 1	13 ± 2	ND	10 ± 1	12 ± 4	24 ± 3	ND	25 ± 3
PiT2ΔR254-V483	NDe	ND	4 ± >1	ND	ND	ND	1 ± >1	1 ± >1
Empty vectorf	<0.0008	<0.002	<0.01	<0.002	<0.001	<0.001	<0.007	<0.003

^aThe experimental setup is described in the text. A-MLV and 10A1 MLV vector pseudotypes were tested on the same precipitates made from CsCl-purified plasmids in experiment 4. In experiment 5, Qiagen maxiprep-purified plasmids were used for preparing precipitates and only the 10A1 MLV vector pseudotype was tested.

^bReceptor and mutant receptor sequences were cloned into pcDNA1A^RtkpA.

^cThe data are averages of three independent transfections ± SEM. The average number of blue cells per three 60-mm-diameter dishes transfected with a plasmid encoding PiT2 was assigned a value of 100% (57,000, 90,000, and 32,000 blue cells per dish for A-MLV in experiment 4 and for 10A1 MLV in experiments 4 and 5, respectively).

^dData are from Bøttger and Pedersen 2004 [31]; please see article for details.

^eND, not determined.

^fValues are based on the detection limit of 1 blue cell per three 60-mm-diameter dishes.