Inward rectifier K+ channel

FIGURE 12-2 The major molecular motifs of ion channels that establish and regulate neuronal excitability in the central nervous system. A. The a subunits of the Ca2+ and Na+ channels share a similar presumptive six-transmembrane structure, repeated four times, in which an intramembranous segment separates transmembrane segments 5 and 6. B. The Ca2+ channel also requires several auxiliary small proteins (a2, b, g, and d). The a2 and d subunits are linked by a disulfide bond (not shown). Regulatory subunits also exist for Na+ channels. C. Voltage-sensitive K+ channels (K ) and the rapidly activating K+ channel (Ka) share a similar presumptive six-transmembrane domain similar in overall configuration to one repeat unit within the Na+ and Ca2+ channel structure, while the inwardly rectifying K+ channel protein (Kir) retains the general configuration of just loops 5 and 6. Regulatory b subunits (cystosolic) can alter Kv channel functions. Channels of these two overall motifs can form heteromultimers.

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Blood Pressure Health

Blood Pressure Health

Your heart pumps blood throughout your body using a network of tubing called arteries and capillaries which return the blood back to your heart via your veins. Blood pressure is the force of the blood pushing against the walls of your arteries as your heart beats.Learn more...

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