TABLE 1.

Enzymatic activities and genes required for cell wall polymer synthesis and remodeling in S. cerevisiae

Process	Activitya	Geneb	Protein function/comment
β-1,3-Glucan synthesis	β-1,3-GS	FKS1	Catalytic subunit of β-1,3-glucan synthase
		GSC2	Catalytic subunit of β-1,3-glucan synthase
		RHO1	GTP-binding protein, regulatory subunit of β-1,3-glucan synthase
		FKS3	Protein with similarity to Fks1p and Gsc2p
β-1,6-Glucan synthesis	β-1,6 GS	RHO1	Probable regulatory subunit of β-1,6-synthase
	Unknown	BIG1	ER membrane protein required for cell wall β-1,6-glucan synthesis
		KRE1	Cell wall glycoprotein involved in β-glucan assembly
		KRE5	UGGT-related protein required for β-1,6-glucan biosynthesis
		KRE6	Protein required for β-1,6-glucan biosynthesis
		KRE9	Glycoprotein involved in cell wall β-glucan assembly
		KNH1	Kre9p homologue
		ROT1	Protein required for cell wall function
		SKN1	Type II membrane protein with similarity to Kre6p
Chitin synthesis	CSI	CHS1	Required for repairing the chitin septum after separation
	CSII	CHS2	Makes chitin in the primary septum during cytokinesis
	CSIII	CHS3	Makes the majority of cell wall chitin, the chitin ring during bud emergence, and spore wall chitosan
		SKT5	Activator of Chs3p, recruits Chs3p to the bud neck via an interaction with Bni4p
		SHC1	Sporulation-specific activator of Chs3p with similarity to Skt5p
Chitosan synthesis	Chitin deacetylase	CDA1	Involved in biosynthesis of ascospore wall chitosan
		CDA2	Involved in biosynthesis of ascospore wall chitosan
Protein mannosylation	α-1,6-MT	OCH1	N-glycan outer chain initiation
	α-1,2/6-MT	MNN9	ManPol I and II subunits involved in N glycosylation
	α-1,6-MT	VAN1	ManPol I subunit involved in N glycosylation
		ANP1	ManPol II subunit involved in N glycosylation
		HOC1	ManPol II subunit involved in N glycosylation
		MNN10	ManPol II subunit involved in N glycosylation
		MNN11	ManPol II subunit involved in N glycosylation
	α-1,3-MT	MNN1	Involved in N glycosylation termination and O mannosylation
	α-1,2-MT	MNN2	Branching of outer chain of N glycosylation
		MNN5	N-glycan outer chain extension
		MNT2	α-1,3-Mannosyltransferase involved in O mannosylation
		MNT3	α-1,3-Mannosyltransferase involved in O mannosylation
	α-1,2 MT	KRE2	KTR family member involved in N and O glycosylation
		KTR1	KTR family member involved in N and O glycosylation
	MT	KTR2	KTR family member involved in N and O glycosylation
		KTR3	KTR family member involved in N and O glycosylation
		YUR1	KTR family member involved in N and O glycosylation
		KTR4	Putative mannosyltransferase
		KTR5	Putative mannosyltransferase
		KTR7	Putative mannosyltransferase
	α-1,2-MpT	KTR6	α-1,2-Mannosylphosphate transferase involved in N glycosylation
Glucan processing/remodeling	β-1,3-Glucan elongase	GAS1	β-1,3-Glucanosyltransferase
	Exo-β-1,3/1,6-glucanase	EXG1	Major exo-β-1,3-glucanase of the cell wall
		EXG2	GPI-anchored plasma membrane exo-β-1,3-glucanase
		SPR1	Sporulation-specific exo-β-1,3-glucanase
	Endo-β-1,3-glucanase	BGL2	Can link in vitro β-1-3-glucan chains through a β-1,6-linkage
		DSE4	Involved in septum degradation
	Glucanase like	DSE2	Glucanase-like secreted protein involved in septum degradation
		EGT2	GPI-anchored cell wall endoglucanase required for proper cell separation after cytokinesis
		GAS2	GAS family member
		GAS3	GAS family member
		GAS4	GAS family member
		GAS5	GAS family member
		SCW3	Glucanase-like “soluble” cell wall protein
		SCW4	Glucanase-like “soluble” cell wall protein
		SCW10	Glucanase-like “soluble” cell wall protein
		SCW11	Glucanase-like protein
Chitin processing	Chitinase	CTS1	Endochitinase, required for cell separation after mitosis
		CTS2	Sporulation-specific endochitinase-like protein
Glucan/chitin cross-linking	Transglycosidase	CRH1	Putative glycosidase of the cell wall
		UTR2	Putative GPI-anchored glycosidase localized to the bud neck
		CRR1	Protein with similarity to Crh1p

^aMT, mannosyltransferase; MpT, mannosylphosphate transferase.

^bGenes whose products have no known or established enzymatic activity are in boldface.