PinX1 the tail on the chromosome
F. Brad Johnson
F. Brad Johnson
Published March 23, 2011
Citation Information: J Clin Invest. 2011;121(4):1242-1244. https://doi.org/10.1172/JCI57024.
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Commentary

PinX1 the tail on the chromosome

Abstract

The PinX1 protein inhibits telomerase, an enzyme that lengthens telomeres — the structures that protect the ends of chromosomes. Loss of PinX1 leads to increased telomere length along with defects in chromosome dynamics. In this issue of the JCI, Zhou et al. present novel evidence from human tumors and mouse models indicating that PinX1 is a clinically significant tumor suppressor. Importantly, the genome-destabilizing effects of PinX1 loss appear to depend on telomerase activity, raising new models and questions for how telomeres and telomerase contribute to the development of cancer.

Authors

F. Brad Johnson

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Figure 1

Consequences of insufficient PinX1 that may contribute to chromosome instability and cancer.

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Consequences of insufficient PinX1 that may contribute to chromosome ins...
The chromosome instability observed in cultured PinX1+/– MEFs required both TERT and TERC components of telomerase, and so the processes that are known or suspected to require TERT and TERC are indicated. The chromosome instability, and presumably cancer, in PinX1+/– mice is due to a single process, or some combination of processes, that depend on telomerase and are sensitive to PinX1 dosage. However, the key processes are not known, and processes not yet defined could be involved. Speculative or uncertain aspects of the figure are indicated by question marks.