A T-cell receptor gamma/CD3 complex found on cloned functional lymphocytes

Cloned blood lymphocytes that do not express the alpha- and beta-chains of the T-cell receptor show MHC-unrestricted cytotoxicity. These cells carry the gamma-protein, disulphide-linked either to another molecule or to itself, and associated with the CD3 complex. These observations may help to solve the mystery posed by the discovery of the gamma gene.     

Aberrant splicing of the CHM gene is a significant cause of choroideremia.

Choroideremia (CHM) is an X-linked progressive degeneration of the choroid and retina. 12% of unrelated male patients carry deletions of the partially cloned CHM gene. In Finland, there are more than 120 living CHM patients belonging to eight apparently unrelated pedigrees. Molecular deletions involving the CHM gene have been detected in three families. We have screened the remaining five families for point mutations. In one large family a single nucleotide (T) insertion into the donor splice site of exon C leads to two aberrantly spliced mRNAs both producing a premature stop codon. The mutation can be assayed easily by amplification and digestion with Msel. Our findings provide additional evidence for the pathogenetic role of CHM mutations and provide a diagnostic tool for one fifth of the world's known CHM patients.     

Decidua and the control of corpus luteum function,follicular development and pituitary LHRH-responsiveness in pseudopregnant and pregnant rats

Summary The mid-pregnancy rescue of corpora lutea can be mimicked in the pseudopregnant rat by induction of decidual tissue in the uterus: in such rats, around day 10, there is neither luteolysis, nor resumption of follicle-development or increase of the pituitary responsiveness to LHRH. The results suggest that the mid-pregnancy rescue of corpora lutea is caused by a maternal factor.12 February 1987     

Sequence similarity between the mammalian bmi-1 proto-oncogene and the Drosophila regulatory genes Psc and Su(z)2

The bmi-1 proto-oncogene can be activated by Moloney murine leukaemia proviral insertions in E mu-myc transgenic mice. It encodes a highly conserved nuclear protein of 324 amino acids which belongs to a family of proteins containing a putative new zinc-finger. Another closely related member of this family is the mouse protein Mel-18. Here we report on the cloning and characterization of a homologous gene (D-bmi) from Drosophila melanogaster. Our analysis indicates that distinct domains of the mouse Bmi-1 protein, including the putative zinc-finger motif, are highly conserved within the much larger D-Bmi protein. Chromosomal localization and sequence comparison reveal that D-bmi is identical to Posterior Sex Combs (Psc) and indicate that the conserved domains between mouse bmi and Psc are also conserved within Suppressor-2 of Zeste (Su(z)2).     

Mutations in MVK, encoding mevalonate kinase, cause hyperimmunoglobulinaemia D and periodic fever syndrome.

Hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS; MIM 260920) is an autosomal recessive disorder characterized by recurrent episodes of fever associated with lymphadenopathy, arthralgia, gastrointestinal dismay and skin rash. Diagnostic hallmark of HIDS is a constitutively elevated level of serum immunoglobulin D (IgD), although patients have been reported with normal IgD levels. To determine the underlying defect in HIDS, we analysed urine of several patients and discovered increased concentrations of mevalonic acid during severe episodes of fever, but not between crises. Subsequent analysis of cells from four unrelated HIDS patients revealed reduced activities of mevalonate kinase (MK; encoded by the gene MVK), a key enzyme of isoprenoid biosynthesis. Sequence analysis of MVK cDNA from the patients identified three different mutations, one of which was common to all patients. Expression of the mutant cDNAs in Escherichia coli showed that all three mutations affect the activity of the encoded proteins. Moreover, immunoblot analysis demonstrated a deficiency of MK protein in patient fibroblasts, indicating a protein-destabilizing effect of the mutations.     

Reduction of high affinity glutamate uptake in rat hippocampus by two polyamine-like toxins isolated from the venom of the predatory waspphilanthus triangulum F

Summary Two components of the venom of the predatory waspPhilanthus triangulum F. significantly reduce — to a greater or less extent — the high affinity uptake of glutamate in rat hippocampus. A concentration of 10 M -PTX caused a reduction of 74%, while the other component, -PTX, at the same concentration, caused a reduction of 18%. Hence the effect of -PTX on high affinity glutamate uptake in the hippocampus is comparable with its effect on high affinity glutamate uptake in insect neuromuscular junctions. Contrary to our previous findings that -PTX has no effect on high affinity glutamate uptake in insect glutamatergic terminal axons, however, -PTX significantly reduces high affinity glutamate uptake in the hippocampus, albeit less effectively than -PTX.