Ribosomal protein S6 cDNA from two Aedes mosquitoes encodes a carboxyl-terminal extension that resembles histone H1 proteins

Ribosomal protein S6 (rpS6) is the major phosphorylated protein on the euka ryotic ribosome. Because electrophoretic evidence suggested that the homolo g of rpS6 from the mosquitoes Aedes albopictus and Aedes aegypti was measur ably larger than Drosophila rpS6, we have now isolated full-length cDNAs en coding Aedes albopictus and Aedes aegypti rpS6. The mosquito rpS6 cDNAs enc oded a 100 amino acid extension at the carboxyl-terminus, relative to rpS6 from humans and Drosophila. This region had homology to cDNAs encoding hist one H1 from various species and accounted for the larger size of the mosqui to protein on polyacrylamide gels. On Northern blots, the mosquito cDNA hyb ridized to a single band measuring approximately 1.2 kb.