Oscillatory AAA + ATPase Knk1 constitutes a novel morphogenetic pathway in fission yeast

Significance We describe a novel pathway controlling fission yeast cell morphogenesis depending on Knk1, a member of the conserved ATPases associated with various cellular activities (AAA+ ) family regulating important cellular processes in all organisms and often functioning in unfolding, degradation, or dissociation of multimeric complexes. Deletion ofknk1 (kink, encoded by SPBC947.01/alf1) founds a new class of morphogenesis mutants exhibiting sudden changes in directional growth. Knk1 performs oscillations between the two cell ends at a periodicity different from the reported cell division cycle 42 oscillations. We conclude that at least two oscillatory systems may coexist in fission yeast to control cell morphogenesis. We speculate that oscillatory properties could represent a key feature of morphogenetic factors to control the growth machinery in a dynamic manner and achieve an accurate definition of cell shape.