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J Mahaffey

Publications and source records attributed to J Mahaffey.

4 recordsLinked to original sources
PubMed1998

A family of Drosophila genes encoding quaking-related maxi-KH domains.

We recently identified a Drosophila gene, wings held out (who), that specifies a STAR (signal transduction and RNA activation) protein expressed within mesoderm and muscles. Genetic evidence suggests that WHO regulates muscle development and function in response to steroid hormone titer. who is related to the mouse quacking gene, essential for embryogenesis and neural myelination, and gld-1, a nematode tumor suppressor gene necessary for oocyte differentiation, both of which contain RNA binding "maxi-KH" domains presumed to link RNA metabolism to cell signaling. To initiate a broader study of Drosophila WHO-related proteins we used degenerate primers encoding peptides unique to maxi-KH domains to amplify the corresponding genes. We recovered nine genes, all specifying single maxi-KH domain proteins having tripartite regions of similarity that extend over 200 amino acids. One is located within the 54D chromosome subdivision, and one within 58C, while the remaining seven are within the 58E subdivision. At least four of these STAR proteins are expressed in a general manner, suggesting that maxi-KH domains are employed widely in Drosophila.

Amino Acid Sequence↗
PubMed1997

A Drosophila muscle-specific gene related to the mouse quaking locus.

We have characterized a novel muscle-specific gene of Drosophila melanogaster, defined by enhancer trap strain 24B of Brand and Perrimon (1993). We show that transcripts of the gene accumulate within presumptive mesoderm and persist within developing muscles, strongly suggesting that the encoded protein is involved in muscle cell determination and differentiation. cDNA sequences reveal that the Drosophila protein is similar to quaking (64% identity over 210 amino acids), a protein essential for mouse embryogenesis, and gld-1 (53% identity over 162 amino acids) a germ-line-specific tumor suppressing protein of the nematode, Caenorhabditis elegans. We demonstrate that the Drosophila gene resides within the 93F chromosome subdivision, and describe its physical map. Finally, we have used the gene, which we have named quaking-related 93F (qkr93F), to identify a family of closely related KH domains.

Amino Acid Sequence↗
PubMed1988

Lack of cardiovascular tolerance during intravenous cocaine infusions in human volunteers.

Acute tolerance to the cardiovascular effects of cocaine has been hypothesized from experiments in which the plasma concentrations of cocaine were rapidly changing. We studied the cardiovascular responses of 8 male human subjects for 4 hours following intravenous bolus doses of cocaine, and compared these to responses in the same subjects after intravenous bolus doses of cocaine followed by continuous intravenous infusions of cocaine designed to maintain steady state plasma levels of cocaine. We found little evidence of tolerance to the tachycardia and hypertensive effects of cocaine during a four hour exposure. Lack of tolerance to the cardiovascular effects of cocaine may be a factor in some types of cocaine related toxicity among cocaine abusers.

Adult↗