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The β‐tubulin gene from rat and human isolates of Pneumocystis carinii
Author(s) -
Edlind T. D.,
Bartlett M. S.,
Weinberg G. A.,
Prah G. N.,
Smith J. W.
Publication year - 1992
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1111/j.1365-2958.1992.tb02204.x
Subject(s) - pneumocystis carinii , biology , tubulin , gene , cryptococcus neoformans , microbiology and biotechnology , dna , organism , protozoa , polymerase chain reaction , genetics , virology , microtubule , human immunodeficiency virus (hiv) , pneumocystis jirovecii
Summary The development of new drugs for treating Pneumocystis carinii infections in AIDS patients is hampered by the lack of long‐term culture systems, and by our generally limited knowledge of this organism. Recently, however, we observed significant activity of various benzimidazoles against growth of this organism in short‐term cultures. Benzimidazoles inhibit microtubule polymerization; there is strong evidence that the primary target is the β‐tubulin subunit. To understand the basis for benzimidazole activity against P. carinii , and to examine the apparent relatedness of this organism to fungi, we have cloned and sequenced the single β‐tubulin gene from a rat P. carinii isolate. There was 89‐91% identity at the amino acid level to β‐tubulins from filamentous fungi, but only 79‐82% identity to yeast and protozoal β‐tubulins. Also, eight introns were distributed throughout the P. carinii β‐tubulin gene in a pattern characteristic of filamentous fungi. Specific residues previously implicated in benzimidazole sensitivity were conserved in P . carinii β‐tubulin. The polymerase chain reaction was used to amplify a segment of P. carinii β‐tubulin DNA from bronchoalveolar lavages obtained from two patients with AIDS. There was considerable divergence at the DNA level between the human and rat sequences, but 100% identity at the ammo‐acid level.