High impact information on VAM3

• AtVAM3 is localized to the prevacuolar compartment and vacuole and is suggested to function in vesicle transport to the vacuole [1].
• The sgr3-1 mutation appeared to reduce the affinity of AtVAM3 for AtVTI11 or SYP5 [1].
• These results suggest that vesicle transport to the prevacuolar compartment/vacuole in the endodermal cells, mediated by a specific SNARE complex containing AtVAM3 and AtVTI11, plays an important role in shoot gravitropism [1].
• Endodermis-specific expression of SGR3 and ZIG by using the SCR promoter could complement the abnormal shoot gravitropism of each mutant [1].
• Recently, we have begun to characterize AtVAM3p, another Arabidopsis t-SNARE that shows high sequence homology to AtPEP12p [2].

Biological context of VAM3

• These findings suggest that VAM3/SYP22 and SYP23 have overlapping functions and that the vesicle transport mediated by these syntaxins is important for shoot morphogenesis [3].
• Significantly, when compared with the wild-type Ler genome, the wild-type Col-0 genome has a single base pair deletion causing a frameshift mutation in SYP23, a gene with the highest known homology to VAM3/SYP22 [3].
• Identification of an allele of VAM3/SYP22 that confers a semi-dwarf phenotype in Arabidopsis thaliana [3].

Physical interactions of VAM3

• We have found that AtVTI1a also interacts with AtVAM3p, suggesting a role for this t-SNARE in post-Golgi trafficking [2].

Other interactions of VAM3

• We found that two Arabidopsis atvam3 alleles, atvam3-3 and atvam3-4/ssm, accumulate large amounts of TGG1 and TGG2 that are enzymatically active [4].
• SGR1, SGR2, SGR3: novel genetic loci involved in shoot gravitropism in Arabidopsis thaliana [5].

References