High impact information on CAM1

• In a mutant yeast strain lacking the CPBP-encoding gene, the ability to overexpress msrA mRNA and MsrA protein was impaired and MsrA catalytic activity was greatly reduced, suggesting that CPBP may enhance msrA gene expression [1].
• By measuring CPBP cooperative binding to the msrA promoter, we have mapped the CPBP binding site to a 39-bp sequence at the 3' end of the promoter [1].
• This gene, which is unique in the S. pombe genome and is named cam1, encodes 149 amino acids excluding the first methionine and is transcribed into mRNA of 1.2-kb length [2].
• Spores bearing disrupted cam1 halt growth soon after germination and rarely carry out the first cell division, indicating that calmodulin does not exist in excess in those cells [2].
• However, the second form of eEF1Bgamma encoded by the TEF4 gene contains serine 11, which may act catalytically [3].

Biological context of CAM1

• The predicted Cam1 amino acid sequence consists of 415 residues that share 32% identity with the Artemia protein, increasing to 72% when conservative substitutions are included [4].
• A 23-residue sequence in the middle of eEF1Bgamma is essential for the stable dimerization of eEF1Bgamma and the quaternary structure of the eEF1 complex [3].
• A homologue of elongation factor 1 gamma regulates methionine sulfoxide reductase A gene expression in Saccharomyces cerevisiae [1].
• Hence, it was inferred that both Trx1 and Trx2 are involved in the PmsrA-CPBP formation during prolonged oxidative stress conditions [5].
• The cam3 mutation, but not cam1 or cam2, also confers the phenotype for utilizing 5'-AMP, the same phenotype as the amp1 mutation [6].

Anatomical context of CAM1

• Immunocytochemical studies showed that D3R and eEF1Bgamma form clusters on the plasma membrane and their co-localization was evident in these clusters [7].

Associations of CAM1 with chemical compounds

• We have isolated a gene (CAM1) from the yeast Saccharomyces cerevisiae that encodes a protein homologous to the translational cofactor elongation factor-1 gamma (EF-1 gamma) first identified in the brine shrimp Artemia salina [4].
• Compared to the sequence of yeast cytoplasmic valyl-tRNA synthetase, that of the human enzyme displays an NH2-terminal extension of approximately 200 amino acid residues that bears strong sequence similarity to the NH2-terminal moiety of EF-1 gamma (Hsieh, S. L., and Campbell, R. D. (1991) Biochem. J. 278, 809-816) [8].
• The multi-subunit guanine nucleotide exchange factor eEF1B for Saccharomyces cerevisiae Translation Elongation Factor 1A (eEF1A) has catalytic (eEF1Balpha) and noncatalytic (eEF1Bgamma) subunits [9].
• The 110kDa glutathione transferase of Yarrowia lipolytica is encoded by a homologue of the TEF3 gene from Saccharomyces cerevisiae: cloning, expression, and homology modeling of the recombinant protein [10].
• However, a late-onset loss of PmsrA-CPBP binding activity occurred following exposure to H(2)O(2) for 24 hours [5].

References