Complete amino acid sequence for human aldolase B derived from cDNA and genomic clones.

Abstract

Several aldolase B clones from a human liver cDNA library have been identified by using a rabbit aldolase A cDNA as a hybridization probe. The most complete of these, pHL413, is 1389 base pairs long and covers -80% of the length of the mRNA, including 90% of the translated region. The cDNA, pHL413, was used to identify a genomic clone, XHG313, which encoded the remaining amino acids of human aldolase B. We demonstrate that the amino acid and nucleotide sequences of aldolase are strongly conserved even between different isozymes. Furthermore, in the 3'-untranslated regions of the mRNAs for the B isozyme of human and rat there is an extensive stretch of homology. Aldolase B lacks a cysteine at positions 72 and 338 and lacks a histidine at position 361. These residues, which are present in rabbit aldolase A, have previously been proposed to take part in catalysis. Our findings suggest that this may not be the case.Fructose-1,6-bisphosphate aldolase (EC 4.1.2.13) is a glycolytic enzyme that catalyzes the reversible conversion of fructose 1,6-bisphosphate to glyceraldehyde 3-phosphate and dihydroxyacetone phosphate. The enzyme consists of a tetramer of identical 40,000-dalton subunits. In vertebrates, three isozyme forms exist. These can be distinguished by their electrophoretic and catalytic properties (1). The amino acid sequence of the region around the active site lysine has been determined for aldolases from several sources (2-8). The similarities among these sequences suggest that the amino acid sequence of aldolase is greatly conserved throughout vertebrate evolution. The differences show that they are indeed distinct proteins, the products of a family of related genes. The study of the genes for this enzyme is of interest because the expression of isozyme forms is regulated during development and because they represent a poorly characterized class of genes, the so-called "housekeeping genes," which are expressed in all cells.Mammalian tissues express the aldolase isozymes in a well-characterized pattern (9). The The study of the expression of aldolase B is of particular interest. Regulation of the aldolase genes is altered in hepatoma cells (13,14). In transformed liver cells production of the adult isozyme, B, is shut off and the embryonic form, aldolase A, is produced again. Furthermore, in humans deficiencies of aldolase B result in a genetic disorder, hereditary fructose intolerance (15, 16). Determination of the nature of the defect(s) that cause hereditary fructose intolerance at the genetic level and investigation of the regulation of the gene during development and oncogenesis require nucleic acid probes specific for aldolase B.This paper describes the isolation and characterization of several cDNA clones for human aldolase B. From the nucleotide sequence of the cDNAs and a genomic clone, we deduce the entire amino acid sequence for this previously uncharacterized protein. This information allows us to confirm the existence of a high degree of homology between the aldolase isozymes throughou...

Human aldolase isozyme gene: the structure of multispecies aldolase B mRNAs

“…The nucleotide sequence of the human liver aldolase B mRNA along with the amino acid sequence deduced from the possible open reading frame is shown in Figure 2. This clone was identified to be a human aldolase B clone by the comparison of nucleotide sequence with rat aldolase B mRNA (6) several groups (16)(17)(18). There can be found a few discrepancies in amino acid sequences deduced from the nucleotide sequences of cDNAs among the four groups including us (this report).…”

A genetic analysis of extinction: trans-regulation of 16 liver-specific genes in hepatoma-fibroblast hybrid cells.

“…Sixteen recombinant cDNA clones (1,(15)(16)(17)(18)(19)(20)(21)(22)(23) encoding hepatic traits were used as markers in these studies. The designations, identities, and sources of these probes are summarized in Table 1 …”

Common elements on the surface of glycolytic enzymes from Trypanosoma brucei may serve as topogenic signals for import into glycosomes.

“…The g-GAPDH sequence is 53% identical with the human GAPDH sequence (Tso et al, 1985). The g-ALDO sequence is 47% identical with the human ALDO sequence (Rottman et al, 1984).…”