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Kinesin is essential for cell morphogenesis and polarized secretion in Neurospora crassa
Author(s) -
Seiler Stephan,
Nargang Frank E.,
Steinberg Gero,
Schliwa Manfred
Publication year - 1997
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1093/emboj/16.11.3025
Subject(s) - kinesin , biology , morphogenesis , microbiology and biotechnology , organelle , neurospora crassa , microtubule , apical cell , secretion , cell polarity , cell , genetics , biochemistry , mutant , gene
Kinesin is a force‐generating molecule that is thought to translocate organelles along microtubules, but its precise cellular function is still unclear. To determine the role of kinesin in vivo , we have generated a kinesin‐deficient strain in the simple cell system Neurospora crassa . Null cells exhibit severe alterations in cell morphogenesis, notably hyphal extension, morphology and branching. Surprisingly, the movement of organelles visualized by video microscopy is hardly affected, but apical hyphae fail to establish a Spitzenkörper , an assemblage of secretory vesicles intimately linked to cell elongation and morphogenesis in Neurospora and other filamentous fungi. As cell morphogenesis depends on polarized secretion, our findings demonstrate that a step in the secretory pathway leading to cell shape determination and cell elongation cannot tolerate a loss of kinesin function. The defect is suggested to affect the transport of small, secretory vesicles to the site involved in protrusive activity, resulting in the uncoordinated insertion of new cell wall material over much of the cell surface. These observations have implications for the presumptive function of kinesin in more complex cell systems.