Sbe2p and Sbe22p, Two Homologous Golgi Proteins Involved in Yeast Cell Wall Formation

摘要: The cell wall of fungal cells is important for integrity and morphogenesis protects against harmful environmental conditions. yeast a complex structure consisting mainly mannoproteins, glucan, chitin. molecular mechanisms by which the components are synthesized transported to surface poorly understood. We have identified characterized two homologous proteins, Sbe2p Sbe22p, through their suppression chs5 spa2 mutant strain defective in chitin synthesis morphogenesis. Although sbe2 sbe22 null mutants viable, display several phenotypes indicative defects structure. First, sorbitol-remediable lysis defect at 37°C hypersensitive SDS calcofluor. Second, electron microscopic analysis reveals that an aberrant with reduced mannoprotein layer. Finally, immunofluorescence experiments reveal small-budded cells, mislocalize Chs3p, protein involved synthesis. In addition, diploids bud-site selection defect, displaying random budding pattern. A Sbe2p–GFP fusion localizes cytoplasmic patches, cofractionates Golgi proteins. Deletion CHS5, encodes transport Chs3p periphery, lethal combination disruption SBE2 SBE22. Thus, we suggest model Sbe22p from apparatus periphery pathway independent Chs5p.