Tick (Acari: Ixodidae) infestations on Zebu cattle in western Kenya: seasonal dynamics of four species of ticks on traditionally managed cattle.

Publication Type

Journal Article

Journal Name

Proceedings of the National Academy of Sciences of the United States of America

Publication Date

1-1-1990

Abstract

Tritiated photoaffinity analogs of the natural lepidopteran juvenile hormones, JH I and II {epoxy[3H]bishomofarnesyl diazoacetate ([3H]EBDA) and epoxy[3H]homofarnesyl diazoacetate ([3H]EHDA)}, and of the JH analog methoprene {[3H]methoprene diazoketone ([3H]MDK)} were synthesized and used to identify specific JH binding proteins in the larval epidermis of the tobacco hornworm (Manduca sexto). EBDA and EHDA specifically photolabeled a 29-kDa nuclear protein (pi 5.8). This protein and a second 29-kDa protein (pI 6.0) were labeled by MDK, but excess unlabeled methoprene or MDK only prevented binding to the latter. These 29-kDa proteins are also present in larval fat body but not in epidermis from either wandering stage or allatectomized larvae, which lack high-affinity JH binding sites. A 29-kDa nuclear protein with the same developmental specificity as this JH binder bound the DNA of two larval endocuticle genes. A 38-kDa cytosolic protein was also specifically photolabeled by these photoaffinity analogs. The 29-kDa nuclear protein is likely the high-affinity receptor for JH that mediates its genomic action, whereas the 38-kDa cytosolic protein may serve as an intracellular carrier for these highly lipophilic hormones and hormone analogs.

Keywords

DNA binding protein, Epoxybishomofarnesyl diazoacetate, Epoxyhomofarnesyl diazoacetate, Manduca sexta, Methoprene diazoketone

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