Phosphorylation regulates polarisation of chitin synthesis in Candida albicans.
The ability to undergo polarised cell growth is fundamental to the development of almost all walled organisms. Fungi are characterised by yeasts and moulds, and both cellular forms have been studied extensively as tractable models of cell polarity. Chitin is a hallmark component of fungal cell walls. Chitin synthesis is essential for growth, viability and rescue from many conditions that impair cell-wall integrity. In the polymorphic human pathogen Candida albicans, chitin synthase 3 (Chs3) synthesises the majority of chitin in the cell wall and is localised at the tips of growing buds and hyphae, and at the septum. An analysis of the C. albicans phospho-proteome revealed that Chs3 can be phosphorylated at Ser139. Mutation of this site showed that both phosphorylation and dephosphorylation are required for the correct localisation and function of Chs3. The kinase Pkc1 was not required to target Chs3 to sites of polarised growth. This is the first report demonstrating an essential role for chitin synthase phosphorylation in the polarised biosynthesis of fungal cell walls and suggests a new mechanism for the regulation of this class of glycosyl-transferase enzyme.
School of Medical Sciences, Institute of Medical Sciences, University of Aberdeen, Foresterhill, Aberdeen, AB25 2ZD, Scotland, UK.
Megan D
MD
Lenardon
Sarah A
SA
Milne
Héctor M
HM
Mora-Montes
Florian A R
FA
Kaffarnik
Scott C
SC
Peck
Alistair J P
AJ
Brown
Carol A
CA
Munro
Neil A R
NA
Gow
D000595:Amino Acid Sequence; D002176:Candida albicans / Q000166:cytology / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology; D016764:Cell Polarity; D002686:Chitin / Q000096:biosynthesis*; D002687:Chitin Synthase / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D025301:Hyphae / Q000378:metabolism / Q000648:ultrastructure; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D010766:Phosphorylation; D011493:Protein Kinase C / Q000235:genetics / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
D005656:Fungal Proteins; D007527:Isoenzymes; D011993:Recombinant Fusion Proteins; D002686:Chitin; D002687:Chitin Synthase; D011493:Protein Kinase C