Table 1.

Summary of point mutations in constructs derived from AKAR2 and of responses to PKA activation

Probe	CFP-based fluorescent domain									T391a	Citrine-based fluorescent domain									FSK response, ΔF/F (%; N, n)
	K26	F64	S65	Y66	N146	M153	V163	N164	A206		S65	Y66	V68	Q69	S72	Y145	H148	T203	H231	BHK	Neurons
AKAR2.1	R	L	T	W	I	T	A	H			G		L	M	A			Y	I	NT	NT
GAkdY	R	L	T		I	T	A	H			G		L	M	A	W	V	Y	I	32 ± 12; 8, 53	44 ± 10; 3, 20
GAkmutdY	R	L	T		I	T	A	H		A	G		L	M	A	W	V	Y	I	NR; 3, 27	NT
GmutAkdYmut	R	L	G	G	I	T	A	H			G	G	L	M	A	W	V	Y	I	NF; 5, 0	NT
GAkdYmut	R	L	T		I	T	A	H			G	G	L	M	A	W	V	Y	I	40 ± 16; 10, 59	74 ± 18; 7, 19
GAk	R	L	T		I	T	A	H												26 ± 10; 8, 52	47 ± 9; 6, 15
GA206KAk	R	L	T		I	T	A	H	K											31 ± 11; 5, 27	NT
eGAk		L	T				A													NR; 5, 34	NT
GI146NAk	R	L	T			T	A	H												NR; 5, 46	NT
GR26KAk		L	T		I	T	A	H												28 ± 12; 5, 24	NT
GT153MAk	R	L	T		I		A	H												28 ± 12; 7, 29	NT
GH164NAk	R	L	T		I	T	A													27 ± 9; 5, 25	NT
CAk	R	L	T	W	I	T	A	H												−20 ± 6; 7, 51	−16 ± 5; 7, 21
GmutAkdY	R	L	G	G	I	T	A	H			G		L	M	A	W	V	Y	I	−17 ± 8; 7, 50	−19 ± 7; 8, 31
GmutAkY	R	L	G	G	I	T	A	H			G		L	M	A			Y	I	NR; 7, 63	NT

Mutations refer to the sequence of wild-type GFP (position 47; accession no. M62653). Numbering begins with the start methionine of each fluorescent domain except for the mutation in the PKA-sensing domain. Citrine-based fluorescent domain is absent where all columns are blank. ΔF/F values are means ± sd. N, total number of experiments n, total number of cells; NF, not fluorescent; NR, not responsive; NT, not tested.

^aPKA sensor domain.