High impact information on VTI11

• Protein pull-down and coimmunoprecipitation experiments reveal that Arabidopsis EPSIN1 interacts with clathrin, VTI11, gamma-adaptin-related protein (gamma-ADR), and vacuolar sorting receptor1 (VSR1) [1].
• By contrast, in zig/sgr4 mutants, where a SNARE molecule functioning in vacuole biogenesis has been disrupted, the movement of amyloplasts in the endodermis is severely restricted both before and after gravistimulation by reorientation [2].
• Only VTI11 and VTI12 are expressed at appreciable levels [3].
• Here, we show that the vti11 zig mutant has defects in vascular patterning and auxin transport [3].
• The sgr2 and zig/sgr4 mutants exhibited abnormal gravitropism in both inflorescence stems and hypocotyls [4].

Biological context of VTI11

• The zig-1 mutant of Arabidopsis lacking Qb-SNARE VTI11 shows little shoot gravitropism and abnormal stem morphology [5].
• The zip1 mutation may be an indication of the flexibility in plant cell function afforded by gene duplication, particularly among the VTI11 genes and their recently diverged orthologs [5].
• In addition, these mutants showed normal phototropic responses, suggesting that SGR4, SGR5 and SGR6 genes are specifically involved in gravity perception and/or gravity signal transduction for the shoot gravitropic response [6].

Anatomical context of VTI11

• Based on these data, we propose that EPSIN1 plays an important role in the vacuolar trafficking of soluble proteins at the trans-Golgi network via its interaction with gamma-ADR, VTI11, VSR1, and clathrin [1].
• The ZIG gene was found to encode AtVTI11, a protein that is homologous with yeast VTI1 and is involved in vesicle transport [4].

Associations of VTI11 with chemical compounds

• We have also cloned another soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE), ZIG/AtVTI11, a mutation that causes abnormal gravitropism [7].

Co-localisations of VTI11

• Using subcellular fractionation and immunoelectron microscopy, we show that AtVTI1a colocalizes with the putative vacuolar cargo receptor AtELP on the trans-Golgi network and the PVC [8].
• AtVTI1a also colocalizes with the t-SNARE AtPEP12p to the PVC [8].

Other interactions of VTI11

• The plant vesicle-associated SNARE AtVTI1a likely mediates vesicle transport from the trans-Golgi network to the prevacuolar compartment [8].
• In addition, AtVTI1a and AtPEP12p can be coimmunoprecipitated from plant cell extracts [8].
• The sgr3-1 mutation appeared to reduce the affinity of AtVAM3 for AtVTI11 or SYP5 [7].

Analytical, diagnostic and therapeutic context of VTI11

• These observations indicate that ZIG and SGR2 are involved in the formation and function of the vacuole, a notion supported by the results of subcellular analysis of the sgr2 and zig mutants with electron microscopy [9].

References