6.5 Mechanotransduction
99
Fig. 6.14 Left: Iinteraction between focal adhesions and cytoskeleton. (1) Myosin-dependent contractility affects mechanosensitive proteins in the module linking actin to a focal adhesion. (2) The
back effect of the mechanical force felt by the substrate or the intracellular matrix on the actin
cytoskeleton. (3) Release of signaling protein molecules. (4) Cytoskeleton-regulating proteins affect actin polymerization and actomyosin contractility, thereby modulating the force-generating
machinery. Top right: Maturation of an adherens junction driven by tension in the actin fibres,
seen as extended lines in the nascent junction on the left. Red and green lines indicate cell membranes, formin molecules are shown by black rectangles, and binding proteins are blue. Bottom
right: Formins trigger polymerization of actin monomers (shown by triangles with the pointed end
directed downward). A protein molecule initiating branching is shown by the black triangle
Mechanotransduction, the conversion of mechanical forces into structurally relevant information, plays an important role in the various developmental processes,
as well as in pathology, such as the spread of cancer (Hoffman et al, 2011). One of
the important ways it works, as schematized in Fig. 6.14, is by breaking weak (noncovalent) molecular bonds and hence modifying protein conformations, as shown
in Fig. 6.15. The cellular response to forces transmitted through focal adhesions
and adherens junctions may be much faster than the response to chemical clues. As
mentioned in the preceding section, parameters of vertex models are just surrogates
for actual complex interactions.
Ambitious attempts at a theory of morphomechanics, stressing the active role
of mechanical factors in development, were independently pursued, starting in the
force
force
Signalling Reinforcement
Energy
Energy
×
change of energy landscape
change of conforma1on
Fig. 6.15 Change in the energy landscape (left) and the resulting conformation and function
changes (right) under an applied force
99
Fig. 6.14 Left: Iinteraction between focal adhesions and cytoskeleton. (1) Myosin-dependent contractility affects mechanosensitive proteins in the module linking actin to a focal adhesion. (2) The
back effect of the mechanical force felt by the substrate or the intracellular matrix on the actin
cytoskeleton. (3) Release of signaling protein molecules. (4) Cytoskeleton-regulating proteins affect actin polymerization and actomyosin contractility, thereby modulating the force-generating
machinery. Top right: Maturation of an adherens junction driven by tension in the actin fibres,
seen as extended lines in the nascent junction on the left. Red and green lines indicate cell membranes, formin molecules are shown by black rectangles, and binding proteins are blue. Bottom
right: Formins trigger polymerization of actin monomers (shown by triangles with the pointed end
directed downward). A protein molecule initiating branching is shown by the black triangle
Mechanotransduction, the conversion of mechanical forces into structurally relevant information, plays an important role in the various developmental processes,
as well as in pathology, such as the spread of cancer (Hoffman et al, 2011). One of
the important ways it works, as schematized in Fig. 6.14, is by breaking weak (noncovalent) molecular bonds and hence modifying protein conformations, as shown
in Fig. 6.15. The cellular response to forces transmitted through focal adhesions
and adherens junctions may be much faster than the response to chemical clues. As
mentioned in the preceding section, parameters of vertex models are just surrogates
for actual complex interactions.
Ambitious attempts at a theory of morphomechanics, stressing the active role
of mechanical factors in development, were independently pursued, starting in the
force
force
Signalling Reinforcement
Energy
Energy
×
change of energy landscape
change of conforma1on
Fig. 6.15 Change in the energy landscape (left) and the resulting conformation and function
changes (right) under an applied force