TABLE 1.

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

ProcessActivityaGenebProtein function/comment
β-1,3-Glucan synthesisβ-1,3-GSFKS1Catalytic subunit of β-1,3-glucan synthase
GSC2Catalytic subunit of β-1,3-glucan synthase
RHO1GTP-binding protein, regulatory subunit of β-1,3-glucan synthase
FKS3Protein with similarity to Fks1p and Gsc2p
β-1,6-Glucan synthesisβ-1,6 GSRHO1Probable regulatory subunit of β-1,6-synthase
UnknownBIG1ER membrane protein required for cell wall β-1,6-glucan synthesis
KRE1Cell wall glycoprotein involved in β-glucan assembly
KRE5UGGT-related protein required for β-1,6-glucan biosynthesis
KRE6Protein required for β-1,6-glucan biosynthesis
KRE9Glycoprotein involved in cell wall β-glucan assembly
KNH1Kre9p homologue
ROT1Protein required for cell wall function
SKN1Type II membrane protein with similarity to Kre6p
Chitin synthesisCSICHS1Required for repairing the chitin septum after separation
CSIICHS2Makes chitin in the primary septum during cytokinesis
CSIIICHS3Makes the majority of cell wall chitin, the chitin ring during bud emergence, and spore wall chitosan
SKT5Activator of Chs3p, recruits Chs3p to the bud neck via an interaction with Bni4p
SHC1Sporulation-specific activator of Chs3p with similarity to Skt5p
Chitosan synthesisChitin deacetylaseCDA1Involved in biosynthesis of ascospore wall chitosan
CDA2Involved in biosynthesis of ascospore wall chitosan
Protein mannosylationα-1,6-MTOCH1N-glycan outer chain initiation
α-1,2/6-MTMNN9ManPol I and II subunits involved in N glycosylation
α-1,6-MTVAN1ManPol I subunit involved in N glycosylation
ANP1ManPol II subunit involved in N glycosylation
HOC1ManPol II subunit involved in N glycosylation
MNN10ManPol II subunit involved in N glycosylation
MNN11ManPol II subunit involved in N glycosylation
α-1,3-MTMNN1Involved in N glycosylation termination and O mannosylation
α-1,2-MTMNN2Branching of outer chain of N glycosylation
MNN5N-glycan outer chain extension
MNT2α-1,3-Mannosyltransferase involved in O mannosylation
MNT3α-1,3-Mannosyltransferase involved in O mannosylation
α-1,2 MTKRE2KTR family member involved in N and O glycosylation
KTR1KTR family member involved in N and O glycosylation
MTKTR2KTR family member involved in N and O glycosylation
KTR3KTR family member involved in N and O glycosylation
YUR1KTR family member involved in N and O glycosylation
KTR4Putative mannosyltransferase
KTR5Putative mannosyltransferase
KTR7Putative mannosyltransferase
α-1,2-MpTKTR6α-1,2-Mannosylphosphate transferase involved in N glycosylation
Glucan processing/remodelingβ-1,3-Glucan elongaseGAS1β-1,3-Glucanosyltransferase
Exo-β-1,3/1,6-glucanaseEXG1Major exo-β-1,3-glucanase of the cell wall
EXG2GPI-anchored plasma membrane exo-β-1,3-glucanase
SPR1Sporulation-specific exo-β-1,3-glucanase
Endo-β-1,3-glucanaseBGL2Can link in vitro β-1-3-glucan chains through a β-1,6-linkage
DSE4Involved in septum degradation
Glucanase likeDSE2Glucanase-like secreted protein involved in septum degradation
EGT2GPI-anchored cell wall endoglucanase required for proper cell separation after cytokinesis
GAS2GAS family member
GAS3GAS family member
GAS4GAS family member
GAS5GAS family member
SCW3Glucanase-like “soluble” cell wall protein
SCW4Glucanase-like “soluble” cell wall protein
SCW10Glucanase-like “soluble” cell wall protein
SCW11Glucanase-like protein
Chitin processingChitinaseCTS1Endochitinase, required for cell separation after mitosis
CTS2Sporulation-specific endochitinase-like protein
Glucan/chitin cross-linkingTransglycosidaseCRH1Putative glycosidase of the cell wall
UTR2Putative GPI-anchored glycosidase localized to the bud neck
CRR1Protein with similarity to Crh1p
  • a MT, mannosyltransferase; MpT, mannosylphosphate transferase.

  • b Genes whose products have no known or established enzymatic activity are in boldface.