A microtubule (MT) is a tubular stiff filament formed by a URLanization of tubulin proteins. We develop a stochastic kinetic model for studying the strength and stability of a pre-formed attachment of a MT with a rigid wall where the MT is tethered to the wall by a group of  motor proteins. Such an attachment , formed by the specific interactions between the MT and the motors, is an analog of ligand-receptor bonds , the MT and the motors anchored on the wall being the counterparts of the ligand and receptors, respectively. However, unlike other ligands, the length of a MT can change with time because of its polymerization-depolymerization kinetics . The simple model developed here is motivated by the MTs linked to the cell cortex by dynein motors . We present the theory for both force-ramp and force-clamp conditions. In the force-ramp protocol we investigate the strength of the attachment by assuming imposition of a time-dependent external load tension that increases linearly with time till the attachment gets ruptured, we calculate the distribution of the rupture forces that fluctuates from one loading to another. In the force-clamp protocol, to test the stability, we compute the distribution of the lifetimes of the attachments under externally applied time-independent load tension, the results establish the MT-wall attachment to be an analog of a slip-bond  .
 We develop a stochastic kinetic model of a pre-formed attachment of a mictrotuble (MT) with a cell cortex, in which the MT is tethered to the cell by a group of active motor proteins. Such an attachment is a particularly unique case of ligand-receptor bonds : The MT ligand changes its length (and thus binding sites) with time by polymerization-depolymerization kinetics , while multiple motor receptors tend to walk actively along the MT length. These processes, combined with force-mediated unbinding of the motors, result in an elaborate behavior of the MT connection to the cell cortex . We present results for the strength and lifetime of the system through the well-established force-clamp and force-ramp protocols when external tension is applied to the MT. The simulation results reveal that the MT-cell attachment behaves as a catch-bond or slip-bond depending on system parameters. We provide analytical approximations of the lifetime and discuss implications of our results on in-vitro experiments .
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A microtubule (MT) is a tubular stiff filament formed by a URLanization of tubulin proteins.
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for studying the strength and stability
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MT with a rigid wall where
mictrotuble (MT) with a cell cortex, in which
R
wall
cell
A
active
R
, formed by the specific interactions between the MT and the motors, is an analog
is a particularly unique case
R
, the MT and the motors anchored on the wall being the counterparts of the ligand and receptors, respectively. However, unlike other ligands, the length of a MT can change with time because of its
: The MT ligand changes its length (and thus binding sites) with time by
R
. The simple model developed here is motivated by the MTs linked
, while multiple motor receptors tend to walk actively along the MT length. These processes, combined with force-mediated unbinding of the motors, result in an elaborate behavior of the MT connection
D
by dynein motors
R
the theory for both force-ramp and
results for the strength and lifetime of the system through the well-established
R
conditions. In the
and
R
protocol we investigate the strength of
protocols when external tension is applied to the MT. The simulation results reveal that
R
attachment by assuming imposition of a time-dependent external load tension that increases linearly with time till the attachment gets ruptured, we calculate the distribution of the rupture forces that fluctuates from one loading to another. In the force-clamp protocol, to test the stability, we compute the distribution of the lifetimes of the attachments under externally applied time-independent load tension, the results establish the MT-wall attachment to be an analog of a
MT-cell attachment behaves as a catch-bond or
A
depending on system parameters. We provide analytical approximations of the lifetime and discuss implications of our results on in-vitro experiments