ABSTRACT
During its development, a plant shoot progresses from a juvenile to an adult phase of vegetative growth and from a reproductively incompetent to a reproductively competent state. In Arabidopsis, loss-of-function mutations in SQUINT (SQN) reduced the number of juvenile leaves and had subtle effects on inflorescence morphology but had no effect on flowering time or on reproductive competence. SQN encodes the Arabidopsis homolog of cyclophilin 40 (CyP40), a protein found in association with the Hsp90 chaperone complex in yeast, mammals, and plants. Thus, in Arabidopsis, CyP40 is specifically required for the vegetative but not the reproductive maturation of the shoot.
Subject(s)
Arabidopsis/growth & development , Arabidopsis/genetics , Cyclophilins , Amino Acid Sequence , Arabidopsis/anatomy & histology , Arabidopsis/physiology , Carrier Proteins/chemistry , Carrier Proteins/genetics , Carrier Proteins/physiology , Chromosome Mapping , Peptidyl-Prolyl Isomerase F , Exons , Gene Expression Regulation, Plant , Genes, Plant , Heat-Shock Proteins/genetics , Molecular Sequence Data , Mutation , Peptidylprolyl Isomerase/chemistry , Peptidylprolyl Isomerase/genetics , Peptidylprolyl Isomerase/physiology , Phenotype , Plant Leaves/anatomy & histology , Plant Leaves/growth & development , Plant Shoots/growth & development , Plant Shoots/physiology , Reproduction , Sequence Alignment , TemperatureABSTRACT
The comparison of three complete aldolase B genes-including known and putative regulatory elements-is presented. The third aldolase B gene was provided by the complete aldB gene sequence (14803 bp) encoding the rabbit aldolase B isozyme. The promoter sequence alignment included the nonmammalian chicken aldolase B gene and confirms the promoter sequence conservation of those elements where trans-factor binding has been demonstrated in rat aldB. Moreover, the alignment reveals conserved sequences that may represent previously unidentified promoter elements that are present in all aldBs or specifically in the mammalian aldB promoters. One remarkable feature is a poly-purine segment found between the CAAT and TATA elements. In the mammalian promoters, this is exclusively a 9-10 bp poly-dA stretch. The avian promoter has an additional stretch of eight dG-bases immediately upstream of the poly-dA. Alignment of a portion of intron 1 of the chicken, human, and rabbit aldB genes reveals conserved sequences that are likely candidates for a reported positive activation sequence. In addition, the amino acid sequences of all eight known aldolase B isozymes is compared to the other vertebrate aldolases. A number of aldolase B-specific residues are identified that cluster in the carboxyl-portion of the sequence. With the exception of residue C268, these residues are not found near the active site, although, they are likely to be responsible for the substrate specificity of aldolase B.
Subject(s)
Carboxy-Lyases/genetics , Fructose-Bisphosphate Aldolase/genetics , Isoenzymes , Promoter Regions, Genetic , Amino Acid Sequence , Animals , Blotting, Northern , Chickens , Genomic Library , Humans , Models, Genetic , Models, Molecular , Molecular Sequence Data , Rabbits , Rats , Restriction Mapping , Sequence Analysis, DNA , Sequence Homology, Amino AcidABSTRACT
A 2061 bp cDNA encoding a goldfish (Carassius auratus) aldolase was isolated from a goldfish brain library. The deduced 362 amino acid sequence is more similar to vertebrate brain (aldolase C) and muscle aldolases (aldolase A) than to the liver isozymes (aldolase B). Northern blot analysis indicates strong expression of the mRNA in brain but not in liver or muscle, which indicates that this is aldolase C rather than aldolase A. Analysis of all known vertebrate aldolase amino acid sequences reveals five residues; Leu-57, Arg-314, Thr-324, Glu-332, and Gly-350 that are present exclusively in aldolase Cs. The goldfish clone possesses all five residues. The residues are primarily located in the carboxyl-terminal region of the enzyme and may play a role in determining the neuronal isozyme-specific properties of the enzyme. Furthermore, the existence of an aldolase C in a teleost fish has implications with respect to the timing of genome duplication events that are thought to have been critical in vertebrate evolution.
