Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.2.1.7 (BAL)
 1,977 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A functional bacteriophage T4 dam+ gene, which specifies a DNA [adenine-N6]methyltransferase (Dam), was cloned on a 1.8-kb HindIII fragment [Schlagman and Hattman, Gene 22 (1983) 139-156]. Sequence analysis [Macdonald and Mosig, EMBO J. 3 (1984) 2863-2871] revealed two overlapping in-phase open reading frames (ORFs). The 5' proximal ORF initiates translation at an AUG and encodes a 30-kDa polypeptide, whereas the downstream ORF initiates translation at a GUG and encodes a 26-kDa polypeptide. Analysis of BAL 31 deletions in our original dam+ clone has verified that at least one of these overlapping ORFs, in fact, encodes T4 Dam. To investigate where T4 Dam translation is initiated, we have constructed plasmids in which a tac or lambda PL promoter is placed 5' to either the longer ORF or just the shorter ORF. Only clones which contain a promoter in front of the longer ORF produce active T4 Dam. This indicates that the 26-kDa polypeptide alone cannot be T4 Dam. Additional experiments suggest that only the 30-kDa polypeptide is required for enzyme activity and that the shorter ORF is not translated in plasmid-carrying cells. We also present evidence that T4 Dam is capable of methylating 5'-GATC-3', GATm5C, and GAThmC sequences; non-canonical sites (e.g., GACC) are also methylated, but much less efficiently.
 ...
PMID:The DNA [adenine-N6]methyltransferase (Dam) of bacteriophage T4. 307 68

We investigated signal transduction pathways for LTD4 in the human promonocytic cell line U937 known, upon differentiation, to express CysLT1 receptors. We confirmed the presence of high-affinity binding sites for 3H-LTD4, which, in functional studies, displayed the features of CysLT1 receptor. In fact, three potent and selective CysLT1 receptor antagonists were able to completely inhibit LTD4-induced response. In turn, cytosolic Ca2+ ([Ca2+]i) increase (EC50 = 3.4 nM +/- 27% CV) was only partially sensitive to pertussis toxin (PTx) as well as to the prenylation inhibitor fluvastatin and to the specific geranylgeranylation and farnesylation inhibitors BAL 9504 and FPT II. Finally, Clostridium sordellii lethal toxin, inhibitor of the Ras family of GTPases, and FTS, a potent methyltransferase inhibitor, were both able to partially inhibit LTD4-induced [Ca2+] increase, suggesting a role for a Ras family member in [Ca2+]i regulation. In conclusion, in dU937 LTD4 signal transduction involves: (a) at least two pathways, one sensitive and one insensitive to PTx; (b) isoprenylated proteins, such as betagamma subunits and, possibly, a small G protein of the Ras family.
 ...
PMID:Involvement of prenylated proteins in calcium signaling induced by LTD4 in differentiated U937 cells. 1451 64