Biomedical subjects

M K Djé

Publications and source records attributed to M K Djé.

3 recordsLinked to original sources

PubMed1995

Plasmodium falciparum: detection of antifolate resistance by mutation-specific restriction enzyme digestion.

We describe here a rapid procedure to predict the resistance of Plasmodium falciparum to pyrimethamine or cycloguanil. The method consists of amplification by PCR of the DHFR gene followed by restriction enzyme digestion of codons 16 and 108. Three different enzymes are used to cut the wild-type, 108-threonine mutant, and 108-asparagine mutant gene. Since every natural antifolate-resistant isolate identified until now carries a mutation in codon 108, determination of the nature of this codon can predict the sensitivity of any P. falciparum isolate.

Animals↗

PubMed1990

Three genes under different developmental control encode elongation factor 1-alpha in Xenopus laevis.

We have cloned cDNAs encoding two variants of the elongation factor for protein synthesis in Xenopus laevis, called EF-1 alpha. One of these (42Sp50) is expressed exclusively in immature oocytes. It is one of two protein components of a 42S RNP particle that is very abundant in previtellogenic oocytes. The 42S RNP particle consists of various tRNAs, 5S RNA, 42Sp50 and a 5S RNA binding protein (42Sp43). A major function served by 42Sp50 appears to be the storage of tRNAs for later use in oogenesis and early embryogenesis. The second EF-1 alpha variant (EF-1 alpha O) is expressed mainly in oocytes but transiently in early embryogenesis as well. Its mRNA cannot be detected after neurulation in somatic cells. EF-1 alpha O is closely related to a third EF-1 alpha (EF-1 alpha S), discovered originally by Krieg et al. (1). EF-1 alpha S is expressed at low levels in oocytes but actively in somatic cells. The latter two proteins are very similar to known eukaryotic EF-1 alpha from other organisms and presumably function in their respective cell types to support protein synthesis.

Amino Acid Sequence↗

PubMed1987

Thesaurin a, the major protein of Xenopus laevis previtellogenic oocytes, present in the 42 S particles, is homologous to elongation factor EF-1 alpha.

We have purified in SDS X.laevis thesaurin a (Mr 50,000) which is part of the 42 S storage particles. Its N-terminal amino acid is blocked and several peptides obtained by V8 protease treatment were purified and sequenced. As expected from one of the functional roles of the 42 S particles (tRNA binding, protection against deacylation and exchange with the ribosome), the amino acid sequence of thesaurin a was found to be closely related to that of the elongation factor EF-1 alpha. We suggest that all three proteins involved in 5 S RNA and tRNA storage in previtellogenic oocytes, TFIIIA, thesaurin a and thesaurin b, have a dual function: storage and a role in transcription or in protein synthesis.

Amino Acid Sequence↗