Molecular cloning of human terminal deoxynucleotidyltransferase.

Biochemical properties of purified human terminal deoxynucleotidyltransferase.

The kinetic mechanism and limited substrate specificity of purified terminal deoxynucleotidyltransferase from human leukemic cells is described. The reaction which utilizes two substrates, dATP as monomer, and p(dA), as initiator (where n is the chain length from 4 through 50), proceeds by a rapid equilibrium random mechanism. The polymerization reaction occurs only in the presence of a divalen...

Distinct and opposite activities of human terminal deoxynucleotidyltransferase splice variants.

Evidence for potential human TdT (hTdT) isoforms derived from hTdT genomic sequences led us to identify the short isoform (hTdTS), as well as mature long transcripts containing exon XII (hTdTL1) and another including exon VII (hTdTL2) in lymphoid cells. Normal B and T lymphocytes express exclusively hTdTS and hTdTL2, whereas hTdTL1 expression appears to be restricted to transformed lymphoid cel...

Variants Terminal Deoxynucleotidyltransferase Splice Distinct and Opposite Activities of Human

Biosynthesis of murine terminal deoxynucleotidyltransferase.

An immunoprecipitation assay for measuring synthesis of murine terminal deoxynucleotidyltransferase (EC 2.7.7.31) has been developed using rabbit antiserum to calf terminal transferase. The antiserum precipitates a single Mr = 60,000 polypeptide (TdT-60) from all cell lines and tissues that contain enzymologically demonstrable terminal transferase. This polypeptide is not precipitated from labe...

Ubiquitylation of Terminal Deoxynucleotidyltransferase Inhibits Its Activity

Terminal deoxynucleotidyltransferase (TdT), which template-independently synthesizes DNA during V(D)J recombination in lymphoid cells, is ubiquitylated by a BPOZ-2/Cul3 complex, as the ubiquitin ligase, and then degraded by the 26 S proteasome. We show here that TdT is ubiquitylated by the Cul3-based ubiquitylation system in vitro. Because TdT could also be ubiquitylated in the absence of Cul/B...