43rd ANNUAL DROSOPHILA RESEARCH CONFERENCE PROGRAM AND ABSTRACT VOLUME |
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20W Troponin, the main muscle regulatory complex, is a trimer composed by Troponin T, Troponin I and Troponin C. In the literature, an additional protein called troponin H has encoded by TMII gene been identified (Bullard et al 1988, Hanke and Storti, 1988). In this presentation, we will summarize the existing information on the isoform patterns of these proteins at the protein level. In earlier work from our laboratories, we have further characterized the isoform variability of Troponin T at the mRNA level (Benoist et al, 1998) and at the protein level (Domingo et al. 1998). The identification of Troponin I and C at the protein level in classical 2D gels has been delayed by the fact that TnI is very basic and TnC is very acidic. In the case of Troponin C, even the identification of the polypeptide(s) in Drosophila was lagging. By using a combination of the known and inferred properties of Troponin C, we have been able to localize the polypeptides in Drosophila and in crayfish muscles. We have prepared polyclonal antibodies that recognize the TnC and TnI polypeptides. The fact that the antibodies are able to recognize the corresponding Troponin I and C of Drosophila and of a crustacean, the crayfish, indicates that they can be useful in phylogenetic studies covering, at least, the whole arthropod phylum. Furthermore, we have identified the phosphorylation pattern of Troponin H in Drosophila flight muscle and linked the presence of this posttrasnlational modification to the developmental maturation and flight capability of the fly. -Benoist et al., 1998 J. Biol.Chem, , 273(13):7538-46. Bullard et. al., J. Mol. Biol., 1988, 204,621-637. Domingo et al., 1998 J. Muscle Res. Cell Motil, 9(4):393-403 Hanke et al. Mol. Cell. Biol.1988, 8, 3591-3602 -Montgomery et al., 2001 J. Physiol 536.2 , 583-592. |