Igelmann et al. report a novel metabolic cycle, which they name HTC, that converts NADH into the key antioxidant factor NADPH. The HTC is repressed by tumor suppressors p53 and RB, this determines whether oncogene-expressing cells undergo senescence (HTCoff) or malignant transformation (HTCon).

Nonsense suppressors were obtained in a haploid yeast strain containing eight nutritional mutations, that are assumed to be amber or ochre, and the cyc1-179 amber mutation that has a UAG codon corresponding to position 9 in iso-1-cytochrome c. Previous studies established that the biosynthesis and function of iso-1-cytochrome c is compatible with replacements at position 9 of amino acids having...

AIM To analyze factors influencing the efficacy of hormonal suppression of spermatogenesis for male contraception. METHODS A nested case-control study was conducted, involving 43 subjects, who did not achieve azoospermia or severe oligozoospermia when given monthly injections of 500 mg testosterone undecanoate (TU), defined as partial suppressors compared with 855 subjects who had suppressed ...

Nine amber suppressor mutations were isolated in the nematode Caenorhabditis elegans by reverting amber alleles of a sex-determining gene, tra-3. One suppressor maps to a known locus, sup-5 III , but the other eight map to three new loci, sup-21 X (five alleles), sup-22 IV (two alleles) and sup-23 IV (one allele). Amber alleles of tra-3 and of a dumpy gene, dpy-20, were used to measure the effi...

Our understanding of estrogen (17b-estradiol, E2) receptor biology has evolved in recent years with the discovery and characterization of a 7-transmembrane-spanning G protein–coupled estrogen receptor (GPER/GPR30) and the development of GPER-selective functional chemical probes. GPER is highly expressed in certain breast, endometrial, and ovarian cancers, establishing the importance of noninvas...

B cells sense microenvironments through the B cell receptor (BCR) and Toll-like receptors (TLRs). While signals from BCR and TLRs synergize to distinguish self from nonself, inappropriate regulation can result in development of autoimmune disease. Here we show that CD22, an inhibitory co-receptor of BCR, also negatively regulates TLR signaling in B cells. CD22-deficient (Cd22(-/-)) B cells exhi...

We investigated T-T cell interactions in the suppression of contact sensitivity. Suppressor cells that block the efferent limb of sensitivity (Ts-eff) can inhibit the passive transfer of contact sensitivity mediated by 1-fluoro-2,4-dinitrobenzene immune cells (T DH). But, Ts-eff cannot block the passive transfer of TDH which comes from cyclophosphamide (Cy) pretreated sensitized mice. We interp...

An adoptive transfer system was used to examine the capacity of cellular inocula from rats fully tolerant of Ag-B antigens to transfer tolerance to irradiated recipients. Permanent tolerance in these irradiated recipients involved specific suppression of the regenerating immune response. Cells obtained from tissues rich in recirculating lymphocytes were the most effective suppressors. Highly pu...