UMR3348 – Intégrité du génome, ARN et cancer

Publications de l’unité

Année de publication : 2000

S Dutertre, M Ababou, R Onclercq, J Delic, B Chatton, C Jaulin, M Amor-Guéret (2000 May 25)

Cell cycle regulation of the endogenous wild type Bloom’s syndrome DNA helicase.

Oncogene : 2731-8 : DOI : 10.1038/sj.onc.1203595 En savoir plus

Bloom’s syndrome (BS) is a rare human autosomal recessive disorder characterized by an increased risk to develop cancer of all types. BS cells are characterized by a generalized genetic instability including a high level of sister chromatid exchanges. BS arises through mutations in both alleles of the BLM gene which encodes a 3′ – 5′ DNA helicase identified as a member of the RecQ family. We developed polyclonal antibodies specific for the NH2- and COOH-terminal region of BLM. Using these antibodies, we analysed BLM expression during the cell cycle and showed that the BLM protein accumulates to high levels in S phase, persists in G2/M and sharply declines in G1, strongly suggestive of degradation during mitosis. The BLM protein is subject to post-translational modifications in mitosis, as revealed by slow migrating forms of BLM found in both demecolcine-treated cells and in mitotic cells isolated from non-treated asynchronous populations. Phosphatase treatment indicated that phosphorylation events were solely responsible for the appearance of the retarded moieties, a possible signal for subsequent degradation. Together, these results are consistent with a role of BLM in a replicative (S phase) and/or post-replicative (G2 phase) process. Oncogene (2000).