The VTI family of SNARE proteins is necessary for plant viability and mediates different protein transport pathways.
The Arabidopsis genome contains a family of v-SNAREs: VTI11, VTI12, and VTI13. Only VTI11 and VTI12 are expressed at appreciable levels. Although these two proteins are 60% identical, they complement different transport pathways when expressed in the yeast vti1 mutant. VTI11 was identified recently as the mutated gene in the shoot gravitropic mutant zig. Here, we show that the vti11 zig mutant has defects in vascular patterning and auxin transport. An Arabidopsis T-DNA insertion mutant, vti12, had a normal phenotype under nutrient-rich growth conditions. However, under nutrient-poor conditions, vti12 showed an accelerated senescence phenotype, suggesting that VTI12 may play a role in the plant autophagy pathway. VTI11 and VTI12 also were able to substitute for each other in their respective SNARE complexes, and a double-mutant cross between zig and vti12 was embryo lethal. These results suggest that some VTI1 protein was necessary for plant viability and that the two proteins were partially functionally redundant.
Surpin
Marci
M
Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California, Riverside, California 92521, USA.
Zheng
Haiyan
H
Morita
Miyo T
MT
Saito
Cheiko
C
Avila
Emily
E
Blakeslee
Joshua J
JJ
Bandyopadhyay
Anindita
A
Kovaleva
Valentina
V
Carter
David
D
Murphy
Angus
A
Tasaka
Masao
M
Raikhel
Natasha
N
D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism*; D001692:Biological Transport; D002470:Cell Survival / Q000235:genetics / Q000502:physiology; D007210:Indoleacetic Acids / Q000378:metabolism; D008854:Microscopy, Electron; D005810:Multigene Family / Q000235:genetics; D009154:Mutation; D021381:Protein Transport; D050766:Qb-SNARE Proteins; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics* / Q000378:metabolism*; D050600:SNARE Proteins / Q000235:genetics* / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism
D029681:Arabidopsis Proteins; D007210:Indoleacetic Acids; D050766:Qb-SNARE Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D050600:SNARE Proteins; C000598693:VTI13 protein, Arabidopsis; C120751:vesicle transport v-SNARE 11 protein, Arabidopsis; C120752:vesicle transport v-SNARE 12 protein, Arabidopsis