Re: p21 gene

From: Robert Bradbury (
Date: Wed Apr 12 2000 - 07:29:32 MDT

On Wed, 12 Apr 2000, Damien Broderick wrote:

> >Today CNN carried a story about an aging gene called p-21 that is responsible
> >for expressing aging related disease genes

Got a pointer for this?
> p21 is, the web tells me (with various further hotlinks) at
> < a cyclin-dependent kinase inhibitor 1. Induced by p53, and may mediate
> its role in response to DNA damage. >

A cyclin-dependent kinase inhibitor is going to be a cell-cycle
replication blocker.

> p53 is one of the most famous genes linked to cancer, since it inhibits
> transformation into the malignant state except when damaged. So p21 must be
> part of a control feedback loop. Robert?
The last time I checked (years ago), I think p21 was essentially a
duplicate of p53. Which kind of makes no sense, unless perhaps it
detects different types of damage or work at different checkpoints in
the cell cycle.

I would take this report with a grain of salt, as there are going
to be complex overlaps between "cell replication blocking",
"cell senescence", "telomere rundown" and "aging". Teasing out
the exact interactions is going to be difficult. Until we get
all of the genes known, and can exactly study their regulation and
expression patterns, this is going to be a case of the blind
biologists holding onto different parts of the elephant.

Its coming. I'd bet in less than 5 years the whole machinery for
replication, blocking, apoptosis, etc. will be pretty much an
open book.


This archive was generated by hypermail 2b29 : Thu Jul 27 2000 - 14:09:14 MDT