Identification of Potential Calorie Restriction-Mimicking Yeast Mutants with Increased Mitochondrial Respiratory Chain and Nitric Oxide Levels

Table 1

List of potential genetic mimics of CR.

Deletion	NO^a	CLS^b	RLS^c	O2^d	Biological function
ypk1Δ	4.1 ± 1.4	E (0.006)	N (21.5^wt; 23.2^mt; 0.15)	0.8 ± 0.03	Ser/Thr protein kinase; sphingolipid signaling
tps1Δ	3.9 ± 0.9	N (0.18)	N (22^wt; 21.4^mt; 0.65)	1.1 ± 0.04	Trehalose biosynthesis; response to stress
reg1Δ	2.9 ± 0.4	E^e	S (21.5^wt; 17.6^mt; 0.0014)	1.2 ± 0.1	Negative regulation of glucose-repressible genes
soy1Δ	2.9 ± 0.4	E (0.0024)	E (23.5^wt; 35.9^mt; 0.0001)	2.4 ± 0.2	Function unknown; associates with nuclear pore complex
hxk2Δ	2.5 ± 0.8	N^f	E^g	~3^h	Hexokinase; glycolysis
erg4Δ	2.1 ± 0.3	E (0.005)	N (21.5^wt; 23.9^mt; 0.54)	1 ± 0.03	Ergosterol biosynthesis
fyv5Δ	1.8 ± 0.5	E (0.004)	N (22.3^wt; 21.9^mt; 0.25)	1.5 ± 0.02	Ion homeostasis
ipk1Δ	1.8 ± 0.7	N (0.07)	E (21.9^wt; 27.1^mt; 0.0065)	2.3 ± 0.2	Inositol phosphate biosynthesis
gup1Δ	1.7 ± 0.1	E (0.026)	E (21.9^wt; 29^mt; 0.0001)	1.4 ± 0.05	Remodeling the GPI anchors; glycerol transport
lip5Δ	1.7 ± 0.3	N (0.86)	E (22.5^wt; 28.4^mt; 0.01)	0.7 ± 0.05	Biosynthesis of lipoic acid
hhf1Δ	1.7 ± 0.4	E (0.005)	E (21.3^wt; 27.7^mt; 0.0001)	1.8 ± 0.02	Histone H4 proteins; chromatin assembly
dse2Δ	1.7 ± 0.1	E (0.0005)	N/A^i	1.6 ± 0.02	Required for cell separation
avl9Δ	1.6 ± 0.1	N (0.091)	N (23.4^wt; 26.02^mt; 0.2)	0.9 ± 0.01	Conserved protein involved in exocytic transport
utr1Δ	1.6 ± 0.2	E (0.001)	N (22.5^wt; 24.48^mt; 0.52)	1 ± 0.07	Cytosolic NAD kinase
zap1Δ	1.5 ± 0.1	E (0.02)	E^j (22.5^wt; 29.8^mt; 0.0124)	1.6 ± 0.1	Zinc-regulated transcription factor
pkh2Δ	1.4 ± 0.2	E (0.0035)	E (22^wt; 30.5^mt; 0.0001)	2 ± 0.25	Ser/Thr protein kinase; sphingolipid signaling
hxt17Δ	1.3 ± 0.1	E (0.0004)	E (22^wt; 28^mt; 0.0014)	2 ± 0.1	Hexose transporter

This table lists top 15 hits from our screen and the pkh2Δ and hxt17Δ mutants. Mutants listed here were first selected by their “growth” (at least 75% of WT; no severe growth defects) and by “resistance to GSNO” (at least 150% of WT) and then were ranked by NO levels.
^aNumbers show average relative intracellular NO levels ± standard deviation (normalized to wild-type control) (for details, see Section 2). ^bCLS: chronological lifespan, E: extended; N: normal; P values are calculated using the AUC method (area under the curve) (see Section 2). Results of one set of representative experiment (each conducted in triplicate or quadruplicate, 𝑛=3 or 4 independent colonies) are shown. About 2 × 10⁸ cells were analyzed in each sample. ^cRLS: replicative lifespan; E: extended; N: normal; S: short; N/A: not determined. Numbers show (average wild-type RLS; average mutant RLS; P values). P values are calculated using the Wilcoxon rank sums tests. Results of one set of representative experiment are shown. 50 cells (𝑛=50) were analyzed for each strain in each experiment. ^dO₂: relative average oxygen consumption rate ± standard deviation (normalized to wild-type control). ^eReported [53]. ^fReported [54]. ^gReported [6]. ^hReported [12]. ⁱN/A: not available. Cells are sticky, unable to separate. ^jExhibits early cell death.