Page 150 - The Miracle of Hormones

THE MIRACLE OF HORMONES

site in structure to one another. For this reason,
these two hormones stimulate different commu-
nication pathways in the cell. The receptors that
function like a communications station inerra-
bly find the communication module to relay the
message.
If a wrong choice were made at this stage,
the communication network would fail and
the person may die. But the receptors on the
cell's membrane work like experts, ensuring
that communication continues without inter- The insulin hormone.
ruption.
How do receptors that are stimulated by different hormones select
without error the messenger proteins with which they must unite? How
do the receptors successfully perform their functions without making a
fatal error? Recent scientific research has helped us to find the answer to
these questions. The flawless communication within the cells comes
from their perfect design.
Let us consider the SH2 module about which we know most. This
small piece of protein is composed of two main parts. One section of SH2
is the part that attaches firmly to the tail of the receptor. The second sec-
tion of SH2, the section that gives it its basic characteristic, operates like a
code reading device.
The number and arrangement of amino acids in the tail section of
the receptor forms the code of the message being brought to the cell. This
code is only deciphered by a certain kind of SH2 module. It is this same
module that unites with it. Another section of this module unites with a
different module. In this way, a special line of communication is estab-
lished between the membrane and the cell nucleus. In short, all these
complicated operations do not happen at random; they are organized
according to a definite system. This arrangement is another demonstra-
tion that everything has been created in a measured and harmonious
way.

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