[Enigmail] How to use PGP-keys in non-default location

[Arsen HAYRAPETYAN]

Hello,

I am using Mozilla Thunderbird version 1.5.0.12 with Enigmail 0.94 and
GnuPG 1.4.3 on Scientific Linux and I am facing the following problem.
I have PGP keyrings (secret and public) generated using GnuPG
command-line interface, they are kept in some directory in my
filesystem. This directory IS NOT the default ~/.gnupg directory. I
don't want it to be the default ~/.gnupg girectory, because later is
kept on AFS system, and I prefer to keep my keys on the local disc.
When I am trying to sign the e-mail message with PGP key using Enigmail,
I get the error, it seems that Enigmail searches for PGP key to sign
with in default location (~/.gnupg). How can I point Enigmail to other
location in my filesystem to search the keys for?

Many thanks in advance,
Arsen.