Within
molecular
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and bioche ...
and
cell biology
Cell biology (also cellular biology or cytology) is a branch of biology that studies the structure, function, and behavior of cells. All living organisms are made of cells. A cell is the basic unit of life that is responsible for the living and ...
Membrane ruffling (also known as cell ruffling) is the formation of a motile cell surface that contains a meshwork of newly polymerized
actin filaments
Microfilaments, also called actin filaments, are protein filaments in the cytoplasm of eukaryotic cells that form part of the cytoskeleton. They are primarily composed of polymers of actin, but are modified by and interact with numerous other pr ...
. It can also be regarded as one of the earliest structural changes observed in the cell. The GTP-binding protein
Rac
RAC or Rac may refer to:
Organizations
* Radio Amateurs of Canada
* RATCH-Australia Corporation, electricity generator
* Refugee Action Collective (Victoria), Melbourne, Australia
* Religious Action Center of Reform Judaism, US
* Rent-A-Center, ...
is the regulator of this membrane ruffling. Changes in the Polyphosphoinositide metabolism and changes in Ca
2+ level of the cell may also play an important role. A number of actin-binding and organizing proteins localize to membrane ruffles and potentially target to transducing molecules.
Characteristic feature of migrating cells
Membrane ruffling is a characteristic feature of many actively migrating cells. When the membrane is unable to attach to the substrate, the membrane protrusion is recycled back into the cell. The ruffling of membranes is thought to be controlled by a group of enzymes known as
Rho GTPases, specifically
RhoA,
Rac1 and
cdc42.
Bacterial infection
Some bacteria such as
enteropathogenic ''E. coli'' and
enterohemorrhagic ''E. coli'' can induce membrane ruffling by secreting toxins via the
type three secretion system and modifying the host
cytoskeleton. Such toxins include EspT, Map, and SopE, which mimic
RhoGEF and activate endogenous Rho GTPases to manipulate
actin polymerisation in the infected cell.
See also
*
Filopodia
*
Lamellipodia
References
External links
* http://www.reading.ac.uk/nitricoxide/intro/migration/dynamics.htm
Cell biology
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