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Plasma Membrane Ca2+-ATPase (PMCA)

ATP-dependent calcium pump on the basolateral enterocyte membrane that exports calcium into blood during transcellular intestinal calcium absorption.

Also: PMCA1b

PMCA1b is the dominant intestinal isoform and the rate-limiting step of transcellular Ca2+ absorption together with apical TRPV6. Its expression is upregulated by 1,25(OH)2D. The transcellular pathway dominates at low calcium intakes; at high intakes paracellular absorption through tight junctions becomes quantitatively more important.

How one textbook covers it

  • Modern Nutrition in Health and Disease, 12th ed. — Ch 7: Calcium

    PMCA1b is the dominant intestinal isoform and the rate-limiting step of transcellular Ca2+ absorption together with apical TRPV6. Its expression is upregulated by 1,25(OH)2D. The transcellular pathway dominates at low calcium intakes; at high intakes paracellular absorption through tight junctions becomes quantitatively more important.

Related terms

Calbindin, Calcitriol, TRPV6