Homologues of a vacuolar processing enzyme that are expressed in different organs in Arabidopsis thaliana.
Vacuolar processing enzymes (VPEs) are responsible for the maturation of seed proteins. These processing enzymes belong to a novel group of cysteine proteinases with molecular masses of 37 to 39 kDa. We isolated two genes of VPEs from a genomic library of Arabidopsis. The gene products were designated alpha-VPE and beta-VPE, and they were 56% identical in terms of amino acid sequence. The amino acid sequences of alpha-VPE and beta-VPE were also 55% and 67% identical to that of castor bean VPE, respectively. The gene for alpha-VPE had 7 introns, while that of beta-VPE had 8 introns. Northern blot analysis revealed that alpha-VPE is expressed in rosette leaves, cauline leaves and stems of Arabidopsis, while beta-VPE is predominantly expressed in the flowers and buds. Neither alpha-VPE nor beta-VPE is expressed in the siliques. This result strongly suggests that the isolated genes encode isozymes of VPE that are specific to vegetative organs.
Kinoshita
T
T
Department of Cell Biology, National Institute for Basic Biology, Okazaki, Japan.
Nishimura
M
M
Hara-Nishimura
I
I
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics*; D018744:DNA, Plant; D015971:Gene Expression Regulation, Enzymologic; D018506:Gene Expression Regulation, Plant; D007527:Isoenzymes / Q000235:genetics*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid
D018744:DNA, Plant; D007527:Isoenzymes; D003546:Cysteine Endopeptidases; C089278:vacuolar processing enzyme; C098278:vacuolar processing enzyme alpha, Arabidopsis; C098279:vacuolar processing enzyme beta, Arabidopsis