Cloning and characterization of a novel gene encoding a protein tyrosine phosphatase in Drosophila melanogaster
Abstract
The messenger RNA of a novel Drosophila protein tyrosine phosphatase gene (dPTP61F) undergoes alternative splicing to encode two non-receptor-like proteins of 61,000 daltons. This splice selection occurs at the 3$\sp\prime$ end of the message, altering the carboxy termini of the encoded proteins. These carboxy terminal sequences govern the targeting of each PTPase either to a cytoplasmic membrane or to the nucleus. The catalytic activity of the two protein products is similar, suggesting that substrate specificity is modulated by the protein's subcellular location. The proteins encoded by dPTP61F (p61/62m and p61/62n) are expressed in the neuropil of the adult Drosophila brain and at high levels in the $\alpha$ and $\beta$ lobes of the mushroom bodies. Mushroom bodies are structures which are thought to be involved in learning and memory processes in insects. The mRNAs which encode p61/62m and p61/62n are expressed in the cell bodies of the corresponding cells. Mutant Drosophila lines were analyzed by western blotting techniques to determine if they were compromised in their ability to express p61/62m or p61/62n. These mutants showed wing and eye phenotypes but all lines expressed some level of these phosphatases, indicating that the phenotypic changes were not caused by the lack of dPTP61F expression.
Degree
Ph.D.
Advisors
Dixon, Purdue University.
Subject Area
Biochemistry
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