The STE20/germinal center kinase POD6 interacts with the NDR kinase COT1 and is involved in polar tip extension in Neurospora crassa.
Members of the Ste20 and NDR protein kinase families are important for normal cell differentiation and morphogenesis in various organisms. We characterized POD6 (NCU02537.2), a novel member of the GCK family of Ste20 kinases that is essential for hyphal tip extension and coordinated branch formation in the filamentous fungus Neurospora crassa. pod-6 and the NDR kinase mutant cot-1 exhibit indistinguishable growth defects, characterized by cessation of cell elongation, hyperbranching, and altered cell-wall composition. We suggest that POD6 and COT1 act in the same genetic pathway, based on the fact that both pod-6 and cot-1 can be suppressed by 1) environmental stresses, 2) altering protein kinase A activity, and 3) common extragenic suppressors (ropy, as well as gul-1, which is characterized here as the ortholog of the budding and fission yeasts SSD1 and Sts5, respectively). Unlinked noncomplementation of cot-1/pod-6 alleles indicates a potential physical interaction between the two kinases, which is further supported by coimmunoprecipitation analyses, partial colocalization of both proteins in wild-type cells, and their common mislocalization in dynein/kinesin mutants. We conclude that POD6 acts together with COT1 and is essential for polar cell extension in a kinesin/dynein-dependent manner in N. crassa.
Seiler
Stephan
S
Deutsche Forschungsgemeinschaft Research Center of Molecular Physiology of the Brain (CMPB), Abteilung Molekulare Mikrobiologie, Universität Göttingen, D-37077 Göttingen, Germany. sseiler@gwdg.de
Vogt
Nico
N
Ziv
Carmit
C
Gorovits
Rena
R
Yarden
Oded
O
D000595:Amino Acid Sequence; D020134:Catalytic Domain; D016764:Cell Polarity / Q000187:drug effects; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D005656:Fungal Proteins / Q000378:metabolism*; D000081410:Germinal Center Kinases; D025301:Hyphae / Q000166:cytology; D008870:Microtubules / Q000378:metabolism; D020409:Molecular Motor Proteins / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation / Q000187:drug effects / Q000235:genetics; D009492:Neurospora crassa / Q000166:cytology* / Q000187:drug effects / Q000201:enzymology*; D010641:Phenotype; D011485:Protein Binding / Q000187:drug effects; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D021381:Protein Transport / Q000187:drug effects; D016415:Sequence Alignment; D012965:Sodium Chloride / Q000494:pharmacology
D005656:Fungal Proteins; D000081410:Germinal Center Kinases; D020409:Molecular Motor Proteins; D012965:Sodium Chloride; D017346:Protein Serine-Threonine Kinases; D017868:Cyclic AMP-Dependent Protein Kinases