Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.5.1.3 (dihydrofolate reductase)
 5,819 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The murine B-cell hybridoma B9 requires interleukin-6 (IL-6) for its survival and proliferation in vitro. We show here that withdrawal of IL-6 from B9 cultures results in programmed death, concomitant with arrest of the cells in the G1 phase of the cell cycle. Unlike several other systems that undergo programmed cell death, no induction of transcripts corresponding to the testosterone-repressed message-2 or transglutaminase genes is observed during this process. Upon readdition of IL-6 to G1-arrested B9 cells, viability is maintained and entry into S phase occurs after a lag period of 10 to 12 hr. Northern blot analysis showed that the immediate-early mRNAs normally induced shortly after growth factor stimulation in quiescent fibroblasts (c-fos, c-jun, Egr-1, c-myc, JE, and KC), and other growth-related genes (2F1, c-Ha-ras, and p53), are either not induced or remain unchanged during G1 to S phase progression. A correlation was found, however, between the temporal pattern of expression of several G1/S phase genes (dihydrofolate reductase, thymidine kinase, transferrin receptor, and histone H3) and DNA synthesis. These results demonstrate that IL-6-induced viability and growth of hybridoma (and, presumably, plasmacytoma) cells is mediated via novel signal transduction pathways.
 ...
PMID:Suppression of programmed death and G1 arrest in B-cell hybridomas by interleukin-6 is not accompanied by altered expression of immediate early response genes. 170 72

Here, we report the N-terminal glycine (Gly) residue of a target protein can be a candidate primary amine for site-specific protein conjugation catalyzed by microbial transglutaminase (MTG) from Streptomyces mobaraensis. Gly5-enhanced green fluorescent protein (EGFP) (EGFP with five additional Gly residues at its N-terminus) was cross-linked with Myc-dihydrofolate reductase (DHFR) (DHFR with the myc epitope sequence at its N-terminus) to yield DHFR-EGFP heterodimers. The reactivities of additional peptidyl linkers were investigated and the results obtained suggested that at least three additional Gly residues at the N-terminus were required to yield the EGFP-DHFR heterodimeric form. Site-directed mutagenesis analysis revealed marked preference of MTG for amino acids adjacent to the N-terminal Gly residue involved in the protein conjugation. In addition, peptide-protein conjugation was demonstrated by MTG-catalyzed N-terminal Gly-specific modification of a target protein with the myc epitope peptide.
 ...
PMID:N-terminal glycine-specific protein conjugation catalyzed by microbial transglutaminase. 1581 24