Nedd4, a human ubiquitin ligase, affects actin cytoskeleton in yeast cells.
Human Nedd4 ubiquitin ligase is involved in protein trafficking, signal transduction and oncogenesis. Nedd4 with an inactive WW4 domain is toxic to yeast cells. We report here that actin cytoskeleton is abnormal in yeast cells expressing the NEDD4 or NEDD4w4 gene and these cells are more sensitive to Latrunculin A, an actin-depolymerizing drug. These phenotypes are less pronounced when a mutation inactivating the catalytic domain of the ligase has been introduced. In contrast, overexpression of the LAS17 gene, encoding an activator of the Arp2/3 actin nucleating complex, is detrimental to NEDD4w4-expressing cells. The level of Las17p is increased in cells overproducing Nedd4w4 and this depends partially on its catalytic domain. Expression of genes encoding Nedd4 variants, like overexpression of LAS17, suppresses the growth defect of the arp2-1 strain. Our results suggest that human Nedd4 ligase inhibits yeast cell growth by disturbing the actin cytoskeleton, in part by increasing Las17p level, and that Nedd4 ubiquitination targets may include actin cytoskeleton-associated proteins conserved in evolution.
Stawiecka-Mirota
Marta
M
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Pawińskiego 5a, 02-106 Warsaw, Poland.
Kamińska
Joanna
J
Urban-Grimal
Daniele
D
Haines
Dale S
DS
Zoładek
Teresa
T
D000199:Actins / Q000378:metabolism*; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D056827:Endosomal Sorting Complexes Required for Transport; D005455:Fluorescent Antibody Technique; D015966:Gene Expression Regulation, Fungal / Q000187:drug effects / Q000235:genetics; D018014:Gene Transfer Techniques; D006801:Humans; D009154:Mutation; D000075702:Nedd4 Ubiquitin Protein Ligases; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology; D013696:Temperature; D053778:Thiazolidines / Q000494:pharmacology; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000502:physiology*; D051316:Wiskott-Aldrich Syndrome Protein / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology
D000199:Actins; D019086:Bridged Bicyclo Compounds, Heterocyclic; D056827:Endosomal Sorting Complexes Required for Transport; C480361:LAS17 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D053778:Thiazolidines; D051316:Wiskott-Aldrich Syndrome Protein; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618483:Nedd4 protein, human; D044767:Ubiquitin-Protein Ligases; C037067:latrunculin A