Two amino acid sequences direct Aspergillus nidulans protein kinase C (PkcA) localization to hyphal apices and septation sites.
The Aspergillus nidulans ortholog of protein kinase C (pkcA) is involved in the organism's putative cell wall integrity (CWI) pathway, and PkcA also is highly localized at growing tips and forming septa. In the present work we identify the regions within PkcA that are responsible for its localization to hyphal tips and septation sites. To this end, we used serially truncated pkcA constructs and expressed them as green fluorescent protein (GFP) chimeras and identified two regions that direct PkcA localization. The first region is a 10 amino-acid sequence near the carboxyl end of the C2 domain that is required for localization to hyphal tips. Proteins containing this sequence also localize to septation sites. A second region between C2 and C1B (encompassing C1A) is sufficient for localization to septation sites but not to hyphal tips. We also report that localization to hyphal tips and septation sites alone is not sufficient for truncated constructs to complement hypersensitivity to the cell wall compromising agent calcofluor white in a strain bearing a mutation in the pkcA gene. Taken together, these results suggest that localization and stress response might be independent.
Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112 jacksonhayesl@rhodes.edu.
Loretta
L
Jackson-Hayes
Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112.
Terry W
TW
Hill
Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112.
Darlene M
DM
Loprete
Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112.
Claire E
CE
DelBove
Departments of Chemistry and Biology, Rhodes College, Memphis, Tennessee 38112.
Justin A
JA
Shapiro
Tougaloo College, Tougaloo, Mississippi 38174.
Jordan L
JL
Henley
Rust College, Holly Springs, Mississippi 38635.
Omolola O
OO
Dawodu
D020816:Amino Acid Motifs; D001233:Aspergillus nidulans / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D025301:Hyphae / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D011493:Protein Kinase C / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport
D005656:Fungal Proteins; D011493:Protein Kinase C
GFP; localization; protein kinase C; septation