Functional characterization of the pleckstrin homology domain of a cellulose synthase from the oomycete Saprolegnia monoica.
Some oomycetes, for instance Saprolegnia parasitica, are severe fish pathogens that cause important economic losses worldwide. Cellulose biosynthesis is a vital process for this class of microorganisms, but the corresponding molecular mechanisms are poorly understood. Of all cellulose synthesizing enzymes known, only some oomycete cellulose synthases contain a pleckstrin homology (PH) domain. Some human PH domains bind specifically to phosphoinositides, but most PH domains bind phospholipids in a non-specific manner. In addition, some PH domains interact with various proteins. Here we have investigated the function of the PH domain of cellulose synthase 2 from the oomycete Saprolegnia monoica (SmCesA2), a species closely related to S. parasitica. The SmCesA2 PH domain is similar to the C-terminal PH domain of the human protein TAPP1. It binds in vitro to phosphoinositides, F-actin and microtubules, and co-localizes with F-actin in vivo. Our results suggest a role of the SmCesA2 PH domain in the regulation, trafficking and/or targeting of the cell wall synthesizing enzyme.
Division of Glycoscience, School of Biotechnology, Royal Institute of Technology (KTH), AlbaNova University Centre, 106 91 Stockholm, Sweden.
Johanna
J
Fugelstad
Christian
C
Brown
Elvira
E
Hukasova
Gustav
G
Sundqvist
Arne
A
Lindqvist
Vincent
V
Bulone
D000199:Actins / Q000378:metabolism; D000595:Amino Acid Sequence; D001798:Blood Proteins / Q000737:chemistry* / Q000378:metabolism; D045744:Cell Line, Tumor; D019295:Computational Biology; D005964:Glucosyltransferases / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000737:chemistry* / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D010716:Phosphatidylinositols / Q000737:chemistry / Q000378:metabolism; D010750:Phosphoproteins / Q000737:chemistry* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D044762:Saprolegnia / Q000201:enzymology*; D016415:Sequence Alignment
D000199:Actins; D001798:Blood Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C435927:PLEKHA1 protein, human; D010716:Phosphatidylinositols; D010750:Phosphoproteins; C039077:platelet protein P47; D005964:Glucosyltransferases; C478648:cellulose synthase