Abstract
The water-insoluble core of lepidopteran silk is composed of four major proteins, but only three genes have been identified. This study demonstrates that the 29- and 30-kDa components of Galleria mellonella silk are derived from a single gene designated P25. The gene is expressed exclusively in the posterior section of the silk glands as a 2-kb mRNA, which accumulates in the feeding larvae and declines at molting. The mRNA encodes a peptide of 24 864 Da that exhibits 51% identity with the putative product of the P25 gene of Bombyx. The conservation of several amino acid stretches, including the relative positions of all 8 cysteines in the mature polypeptide, implies that the P25 proteins play similar, and apparently significant roles in silk formation in the two species. A Galleria P25 cDNA yields a peptide of about 25 kDa when translated in vitro; the 29- and 30-kDa forms present in the silk are derived from this primary translation product by differential glycosylation.
Similar content being viewed by others
Author information
Authors and Affiliations
Additional information
Received: 4 June 1997 / Accepted: 5 September 1997
Rights and permissions
About this article
Cite this article
Žurovec, M., Kodrík, D., Yang, C. et al. The P25 component of Galleria silk. Mol Gen Genet 257, 264–270 (1998). https://doi.org/10.1007/s004380050647
Issue Date:
DOI: https://doi.org/10.1007/s004380050647