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Post‐translational modification directs nuclear and hyphal tip localization of C andida albicans m RNA ‐binding protein S lr1
Author(s) -
Ariyachet Chaiyaboot,
Beißel Christian,
Li Xiang,
Lorrey Selena,
Mackenzie Olivia,
Martin Patrick M.,
O'Brien Katharine,
Pholcharee Tossapol,
Sim Sue,
Krebber Heike,
McBride Anne E.
Publication year - 2017
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/mmi.13643
Subject(s) - biology , microbiology and biotechnology , candida albicans , phosphorylation , ribosome , rna binding protein , messenger rna , rna , biochemistry , gene
Summary The morphological transition of the opportunistic fungal pathogen Candida albicans from budding to hyphal growth has been implicated in its ability to cause disease in animal models. Absence of S R‐ l ike R NA‐binding protein Slr1 slows hyphal formation and decreases virulence in a systemic candidiasis model, suggesting a role for post‐transcriptional regulation in these processes. SR (serine–arginine)‐rich proteins influence multiple steps in mRNA metabolism and their localization and function are frequently controlled by modification. We now demonstrate that Slr1 binds to polyadenylated RNA and that its intracellular localization is modulated by phosphorylation and methylation. Wildtype Slr1‐GFP is predominantly nuclear, but also co‐fractionates with translating ribosomes. The non‐phosphorylatable slr1‐6SA‐GFP protein, in which six serines in SR/RS clusters are substituted with alanines, primarily localizes to the cytoplasm in budding cells. Intriguingly, hyphal cells display a slr1‐6SA‐GFP focus at the tip near the Spitzenkörper, a vesicular structure involved in molecular trafficking to the tip. The presence of slr1‐6SA‐GFP hyphal tip foci is reduced in the absence of the mRNA‐transport protein She3, suggesting that unphosphorylated Slr1 associates with mRNA–protein complexes transported to the tip. The impact of SLR1 deletion on hyphal formation and function thus may be partially due to a role in hyphal mRNA transport.