Download Cell to Cell Communication

Cell to Cell Communication
Cell Signaling results in a change
in cell activity
Cell to Cell Communication
• Examples:
• neurotransmitters
recognized in
synapse or
neuromuscular
junction
• Antigens triggering
antibody response
• Target cells
responding to specific
hormones
Cell to Cell Communication
• Often involves
specialized receptors
called integrins
• Integins are
transmembrane
proteins that provide
a link between the
interior and exterior of
the cell
Cell to Cell Communication
• Involved in specific
processes such as
differentiation, migration,
proliferation, protein
expression, activation of
growth factors, apoptosis,
and cell survival. Can
also be activated from the
inside to change the cell’s
relationship with its
environment
Kinases, a group of enzymes that
control the cell cycle are activated
by integrins
Cell to Cell Communication
• Integrins are
heterodimers
• Two different protein
strands together
• Alpha and beta
chains
• 24 integrins have
been identified
Integrins
• Basic heterodimer
structure has been
highly conserved
among all animals
• What does this
mean?
• Similar proteins are
also found in plants,
fungi, and
prokaryotes
Integrin Activation
Integrin Activation
• Inactive: bent
• Activated: Upright
• This change occurs when
a protein binds to a small
section of the beta
subunit.
• What attaches to the
integrin is called the
ligand—could be a
hormone, an antigen, etc.
After activation…
• Integrins move within
the cell membrane to
cluster and form
adhesion sites
• These sites bind with
other proteins and
serve as a link to the
cytoskeleton
• Sets off a cascade of
events
Integrin Activation
• May be be outside-in
OR
• Inside out signaling
Cell Signaling causes a change in
cellular activity!
• There will be a result!
Could be initiation of cell
cycle, formation of a
blood clot, activation of
a gene to produce a
protein, etc.