O-acetylation of GD3 prevents its apoptotic effect and promotes survival of lymphoblasts in childhood acute lymphoblastic leukaemia.

We have previously demonstrated induction of O-acetylated sialoglycoproteins on lymphoblasts of childhood acute lymphoblastic leukaemia (ALL). These molecules promote survival of lymphoblasts by preventing apoptosis. Although O-acetylated sialoglycoproteins are over expressed, the status of O-acetylation of gangliosides and their role in lymphoblasts survival remains to be explored in ALL patients.

Apoptotic mode of cell death in substantia nigra following intranigral infusion of the parkinsonian neurotoxin, MPP+ in Sprague-Dawley rats: cellular, molecular and ultrastructural evidences.

The potent parkinsonian neurotoxin 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) is known to cause dopaminergic neurodegeneration in nigrostriatal system. In the present study we investigated the nuclear morphology of cells in the substantia nigra pars compacta (SNpc) region of rats following unilateral intranigral infusion of the active metabolite, 1-methyl-4-phenyl pyridinium ion (MPP(+)), which resulted in a dose-dependent and prolonged dopamine depletion in the ipsilateral striatum. There appeared a substantial loss of tyrosine hydroxylase immunoreactive neurons in the SNpc that received the neurotoxin.

"Ping-pong" interactions between mitochondrial tRNA import receptors within a multiprotein complex.

The mitochondrial genomes of a wide variety of species contain an insufficient number of functional tRNA genes, and translation of mitochondrial mRNAs is sustained by import of nucleus-encoded tRNAs. In Leishmania, transfer of tRNAs across the inner membrane can be regulated by positive and negative interactions between them. To define the factors involved in such interactions, a large multisubunit complex (molecular mass, approximately 640 kDa) from the inner mitochondrial membrane of the kinetoplastid protozoon Leishmania, consisting of approximately 130-A particles, was isolated.