Table 20.2.

Genes that affect mRNA decay

Pathway	Gene	Function of protein	Accumulating intermediate in loss of function (mutant)
Deadenylation	CCR4, CAF1, Pan2	Major deadenylases Minor deadenylase	Adenylated capped mRNA
5′ to 3′-Decay	Dcp2	Decapping enzyme
	Dcp1 Dhh1 Lsm1-7 Pat1	Activator of decapping   enzyme	Deadenylated capped mRNA
	Xrn1	5′ to 3′-exonuclease	Deadenylated decapped mRNA
3′ to 5′-Decay	Ski6 (RRP41), Ski4   (CSL4) RRP4	Components of exosome	Poly(G)-3′-end fragment and a series of 3′ to 5′-   decay intermediates
	Ski2, Ski3, Ski7, Ski8	Modulate 3′ to 5′-   exonuclease activity
Specialized   mRNA decay
	Upf1 Upf2 Upf3	Required for nonsense-mediated   decay
	Hbs1 Dom34	Required for no-go decay
	Ski7	Specifically blocks nonstop   decay