Cell communication
• Introduction to cell signaling
• Cell-cell junctions
Introduction to cell signaling
Learn how cells communicate with one another using different kinds of short- and long-
range signaling in our bodies.
Introduction
Think your cells are just simple building blocks, unconscious and
static as bricks in a wall? If so, think again! Cells can detect what's
going on around them, and they can respond in real time to cues
from their neighbors and environment. At this very moment, your
cells are sending and receiving millions of messages in the form of
chemical signaling molecules!
In this article, we'll examine the basic principles of how cells
communicate with one another. We'll first look at how cell-cell
signaling works, then consider different kinds of short- and long-
range signaling that happen in our bodies.
Overview of cell signaling
Cells typically communicate using chemical signals. These chemical
signals, which are proteins or other molecules produced by
a sending cell, are often secreted from the cell and released into the
extracellular space. There, they can float – like messages in a bottle
– over to neighboring cells.
, Sending cell: this cell secretes a ligand.
Target cell: this cell has a receptor that can bind the ligand. The
ligand binds to the receptor and triggers a signaling cascade inside
the cell, leading to a response.
Nontarget cell: this cell does not have a receptor for the ligand
(though it may have other kinds of receptors). The cell does not
perceive the ligand and thus does not respond to it.
Not all cells can “hear” a particular chemical message. In order to
detect a signal (that is, to be a target cell), a neighbor cell must have
the right receptor for that signal. When a signaling molecule binds
to its receptor, it alters the shape or activity of the receptor,
triggering a change inside of the cell. Signaling molecules are often
called ligands, a general term for molecules that bind specifically to
other molecules (such as receptors).
The message carried by a ligand is often relayed through a chain of
chemical messengers inside the cell. Ultimately, it leads to a change
in the cell, such as alteration in the activity of a gene or even the
induction of a whole process, such as cell division. Thus, the
original intercellular (between-cells) signal is converted into
an intracellular (within-cell) signal that triggers a response.
• Introduction to cell signaling
• Cell-cell junctions
Introduction to cell signaling
Learn how cells communicate with one another using different kinds of short- and long-
range signaling in our bodies.
Introduction
Think your cells are just simple building blocks, unconscious and
static as bricks in a wall? If so, think again! Cells can detect what's
going on around them, and they can respond in real time to cues
from their neighbors and environment. At this very moment, your
cells are sending and receiving millions of messages in the form of
chemical signaling molecules!
In this article, we'll examine the basic principles of how cells
communicate with one another. We'll first look at how cell-cell
signaling works, then consider different kinds of short- and long-
range signaling that happen in our bodies.
Overview of cell signaling
Cells typically communicate using chemical signals. These chemical
signals, which are proteins or other molecules produced by
a sending cell, are often secreted from the cell and released into the
extracellular space. There, they can float – like messages in a bottle
– over to neighboring cells.
, Sending cell: this cell secretes a ligand.
Target cell: this cell has a receptor that can bind the ligand. The
ligand binds to the receptor and triggers a signaling cascade inside
the cell, leading to a response.
Nontarget cell: this cell does not have a receptor for the ligand
(though it may have other kinds of receptors). The cell does not
perceive the ligand and thus does not respond to it.
Not all cells can “hear” a particular chemical message. In order to
detect a signal (that is, to be a target cell), a neighbor cell must have
the right receptor for that signal. When a signaling molecule binds
to its receptor, it alters the shape or activity of the receptor,
triggering a change inside of the cell. Signaling molecules are often
called ligands, a general term for molecules that bind specifically to
other molecules (such as receptors).
The message carried by a ligand is often relayed through a chain of
chemical messengers inside the cell. Ultimately, it leads to a change
in the cell, such as alteration in the activity of a gene or even the
induction of a whole process, such as cell division. Thus, the
original intercellular (between-cells) signal is converted into
an intracellular (within-cell) signal that triggers a response.
