LEISHMANIA-MAJOR - ORGANIZATION AND CONSERVATION OF GENES ENCODING REPETITIVE PEPTIDES AND SUBCELLULAR-LOCALIZATION OF THE CORRESPONDING PROTEINS

Proteins containing tandemly repeating peptide sequences are character istic of several parasite antigens. Previously it was reported that Le ishmania major contain two genes, Lm20 and Lm39, consisting of two unr elated repeat sequences of 42 and 30 base pairs (bp), respectively. In present study L. major was shown to contain two genes that contained the Lm20 42-BP repeat sequence and that the 42-BP repeat sequence was highly conserved among both Old and New World Leishmania species. The two L. major genes varied in the number of 42-BP tandem repeat sequenc es with Lm20.1 containing over 100 repeat units while Lm20.2 contained only 8 repeat units. Furthermore, these two L. major genes were disti nct with respect to the nonrepetitive sequence. The unrelated Lm39 30 BP tandem repeat was also shown to be highly conserved among Leishmani a species. The subcellular localization of the proteins encoded by Lm2 0 42-BP repeat and the Lm39 30-BP repeat were determined by immunoelec tron microscopy. Antibodies raised against synthetic peptides correspo nding to the Lm39 30-BP repeat sequence reacted with proteins that loc alized to the endoplasmic reticulum and membraneous structures within the promastigote cytoplasm. (C) 1994 Academic Press, Inc.