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Regulation mechanism of the lateral diffusion of band 3 in erythrocyte membranes by the membrane skeleton.

Tomishige M, Sako Y, Kusumi A - J. Cell Biol. (1998)

Bottom Line: When the membrane skeletal network was dragged and deformed/translated using optical tweezers, band 3 molecules that were undergoing hop diffusion were displaced toward the same direction as the skeleton.Mild trypsin treatment of ghosts, which cleaves off the cytoplasmic portion of band 3 without affecting spectrin, actin, and protein 4.1, increased the intercompartmental hop rate of band 3 by a factor of 6, whereas it did not change the corral size and the microscopic diffusion rate within a corral.These results indicate that the cytoplasmic portion of band 3 collides with the membrane skeleton, which causes temporal confinement of band 3 inside a mesh of the membrane skeleton.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.

ABSTRACT
Mechanisms that regulate the movement of a membrane spanning protein band 3 in erythrocyte ghosts were investigated at the level of a single or small groups of molecules using single particle tracking with an enhanced time resolution (0.22 ms). Two-thirds of band 3 undergo macroscopic diffusion: a band 3 molecule is temporarily corralled in a mesh of 110 nm in diameter, and hops to an adjacent mesh an average of every 350 ms. The rest (one-third) of band 3 exhibited oscillatory motion similar to that of spectrin, suggesting that these band 3 molecules are bound to spectrin. When the membrane skeletal network was dragged and deformed/translated using optical tweezers, band 3 molecules that were undergoing hop diffusion were displaced toward the same direction as the skeleton. Mild trypsin treatment of ghosts, which cleaves off the cytoplasmic portion of band 3 without affecting spectrin, actin, and protein 4.1, increased the intercompartmental hop rate of band 3 by a factor of 6, whereas it did not change the corral size and the microscopic diffusion rate within a corral. These results indicate that the cytoplasmic portion of band 3 collides with the membrane skeleton, which causes temporal confinement of band 3 inside a mesh of the membrane skeleton.

Show MeSH
(a) A model of the compartmentalized structure of the  plasma membrane with regard to translational diffusion of band  3. A band 3 molecule undergoes almost free diffusion within a  compartment (slowed only by the presence of other membrane  proteins). It sometimes hops from one compartment to an adjacent compartment, and the long-range diffusion of band 3 occurs  as a result of successive intercompartmental hops. (b) Membrane-skeleton fence model. In this figure, the plasma membrane  is viewed from inside the cell. The spectrin network is in close  proximity to the cytoplasmic surface of the plasma membrane.  The cytoplasmic domain of band 3 collides with the membrane  skeleton and cannot readily move to an adjacent compartment.
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Figure 1: (a) A model of the compartmentalized structure of the plasma membrane with regard to translational diffusion of band 3. A band 3 molecule undergoes almost free diffusion within a compartment (slowed only by the presence of other membrane proteins). It sometimes hops from one compartment to an adjacent compartment, and the long-range diffusion of band 3 occurs as a result of successive intercompartmental hops. (b) Membrane-skeleton fence model. In this figure, the plasma membrane is viewed from inside the cell. The spectrin network is in close proximity to the cytoplasmic surface of the plasma membrane. The cytoplasmic domain of band 3 collides with the membrane skeleton and cannot readily move to an adjacent compartment.

Mentions: Based on the results of FRAP and rotational diffusion measurements of band 3 in ghosts with various ratios of spectrin dimers versus tetramers, Tsuji et al. (1988) proposed a spectrin dimer-tetramer equilibrium gate model in which long-range translational diffusion of band 3 molecules that are not bound to the membrane skeleton is restricted by nonspecific barriers imposed by the skeletal network and the rate of translational diffusion is regulated by the fraction of spectrin dimers (open gate) and tetramers (closed gate). Kusumi et al. (1993) proposed a general model to explain the slowness of lateral diffusion of many other membrane proteins in nonerythroid cells (membrane-skeleton fence model; see Fig. 1), in which the cytoplasmic portion of a membrane protein collides with the membrane skeleton, which causes temporal confinement of the membrane protein within a mesh of membrane skeletal network.


Regulation mechanism of the lateral diffusion of band 3 in erythrocyte membranes by the membrane skeleton.

Tomishige M, Sako Y, Kusumi A - J. Cell Biol. (1998)

(a) A model of the compartmentalized structure of the  plasma membrane with regard to translational diffusion of band  3. A band 3 molecule undergoes almost free diffusion within a  compartment (slowed only by the presence of other membrane  proteins). It sometimes hops from one compartment to an adjacent compartment, and the long-range diffusion of band 3 occurs  as a result of successive intercompartmental hops. (b) Membrane-skeleton fence model. In this figure, the plasma membrane  is viewed from inside the cell. The spectrin network is in close  proximity to the cytoplasmic surface of the plasma membrane.  The cytoplasmic domain of band 3 collides with the membrane  skeleton and cannot readily move to an adjacent compartment.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2132872&req=5

Figure 1: (a) A model of the compartmentalized structure of the plasma membrane with regard to translational diffusion of band 3. A band 3 molecule undergoes almost free diffusion within a compartment (slowed only by the presence of other membrane proteins). It sometimes hops from one compartment to an adjacent compartment, and the long-range diffusion of band 3 occurs as a result of successive intercompartmental hops. (b) Membrane-skeleton fence model. In this figure, the plasma membrane is viewed from inside the cell. The spectrin network is in close proximity to the cytoplasmic surface of the plasma membrane. The cytoplasmic domain of band 3 collides with the membrane skeleton and cannot readily move to an adjacent compartment.
Mentions: Based on the results of FRAP and rotational diffusion measurements of band 3 in ghosts with various ratios of spectrin dimers versus tetramers, Tsuji et al. (1988) proposed a spectrin dimer-tetramer equilibrium gate model in which long-range translational diffusion of band 3 molecules that are not bound to the membrane skeleton is restricted by nonspecific barriers imposed by the skeletal network and the rate of translational diffusion is regulated by the fraction of spectrin dimers (open gate) and tetramers (closed gate). Kusumi et al. (1993) proposed a general model to explain the slowness of lateral diffusion of many other membrane proteins in nonerythroid cells (membrane-skeleton fence model; see Fig. 1), in which the cytoplasmic portion of a membrane protein collides with the membrane skeleton, which causes temporal confinement of the membrane protein within a mesh of membrane skeletal network.

Bottom Line: When the membrane skeletal network was dragged and deformed/translated using optical tweezers, band 3 molecules that were undergoing hop diffusion were displaced toward the same direction as the skeleton.Mild trypsin treatment of ghosts, which cleaves off the cytoplasmic portion of band 3 without affecting spectrin, actin, and protein 4.1, increased the intercompartmental hop rate of band 3 by a factor of 6, whereas it did not change the corral size and the microscopic diffusion rate within a corral.These results indicate that the cytoplasmic portion of band 3 collides with the membrane skeleton, which causes temporal confinement of band 3 inside a mesh of the membrane skeleton.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Science, Graduate School of Science, Nagoya University, Chikusa-ku, Nagoya 464-8602, Japan.

ABSTRACT
Mechanisms that regulate the movement of a membrane spanning protein band 3 in erythrocyte ghosts were investigated at the level of a single or small groups of molecules using single particle tracking with an enhanced time resolution (0.22 ms). Two-thirds of band 3 undergo macroscopic diffusion: a band 3 molecule is temporarily corralled in a mesh of 110 nm in diameter, and hops to an adjacent mesh an average of every 350 ms. The rest (one-third) of band 3 exhibited oscillatory motion similar to that of spectrin, suggesting that these band 3 molecules are bound to spectrin. When the membrane skeletal network was dragged and deformed/translated using optical tweezers, band 3 molecules that were undergoing hop diffusion were displaced toward the same direction as the skeleton. Mild trypsin treatment of ghosts, which cleaves off the cytoplasmic portion of band 3 without affecting spectrin, actin, and protein 4.1, increased the intercompartmental hop rate of band 3 by a factor of 6, whereas it did not change the corral size and the microscopic diffusion rate within a corral. These results indicate that the cytoplasmic portion of band 3 collides with the membrane skeleton, which causes temporal confinement of band 3 inside a mesh of the membrane skeleton.

Show MeSH