Structurally distinct genes for the surface protease of Leishmania mexicana are developmentally regulated

• Published in: Molecular and biochemical parasitology Vol. 57; no. 1; p. 31
• Main Authors: Medina-Acosta, E, Karess, R E, Russell, D G
• Format: Journal Article
• Language: English
• Published: Netherlands 01-01-1993
• Subjects: Amino Acid Sequence; Animals; Base Sequence; DNA, Protozoan - genetics; Gene Expression Regulation; Genes, Protozoan; Leishmania - genetics; Leishmania mexicana - enzymology; Leishmania mexicana - genetics; Leishmania mexicana - growth & development; Metalloendopeptidases - genetics; Molecular Sequence Data; Multigene Family; Restriction Mapping; Sequence Homology, Amino Acid
• ISSN: 0166-6851
• DOI: 10.1016/0166-6851(93)90241-O

gp63 is a highly abundant glycosylphosphatidylinositol (GPI)-anchored membrane protein expressed in both the promastigote and the amastigote forms of Leishmania species. In Leishmania mexicana, gp63 exists as a heterogeneous family of proteins that are differentially processed and localized during the 2 developmental stages. In this study we determined the molecular organization of the L. mexicana gp63 gene family, demonstrating that the gp63 genes fall into 3 linked families of tandemly repeated, but structurally distinct, entities designated as C1, C2 and C3. The C1 and C2 gene clusters contain 4-5 copies each, while the C3 gene may be single copy. Whilst promastigotes contain transcripts from all 3 gene classes, the intracellular amastigote only expresses detectable transcript from the C1 gene class. Moreover, the sequence of the C1 genes predicts a unique carboxy terminus substantially different from the GPI anchor addition signal sequence found in other Leishmania spp. and which has characteristics incompatible with substitution with a GPI anchor. These findings have significance for both the diversity of gp63 and for the regulation of tightly clustered, tandem gene arrays.