ATP2B2 Q01814

质膜钙转运ATP酶 2 (PMCA2) (EC 7.2.2.10) (质膜钙ATP酶亚型 2) (质膜钙泵亚型 2)

功能描述

ATP驱动的Ca(2+)离子泵，参与维持小脑回路以及前庭和耳蜗系统特化细胞的基础细胞内Ca(2+)水平 (PubMed:15829536, PubMed:17234811)。利用ATP作为能源，将细胞质Ca(2+)离子跨质膜转运至细胞外间隙 (PubMed:15829536, PubMed:17234811)。具有快速激活和Ca(2+)清除速率，适合控制快速神经元Ca(2+)动力学。在平行纤维到浦肯野神经元突触处，介导响应攀爬纤维诱导的Ca(2+)升高的突触前Ca(2+)外排。促使Ca(2+)浓度快速恢复至静息水平，最终有助于长时程抑制的诱导和运动学习 (By similarity)。在听觉和平衡中发挥重要作用 (PubMed:15829536, PubMed:17234811)。在耳蜗毛细胞中，将Ca(2+)离子从静纤毛穿梭转运至内淋巴，并耗散由机械电转导通道开放产生的Ca(2+)瞬变。调节前庭系统中的Ca(2+)水平，有助于耳石的形成 (PubMed:15829536, PubMed:17234811)。在非兴奋性细胞中，通过空间控制Ca(2+)离子外排和耗散由库操纵通道产生的Ca(2+)瞬变来调节Ca(2+)信号传导 (PubMed:25690014)。在哺乳期乳腺中，使乳汁中含有高浓度的Ca(2+)离子 (By similarity)。 {ECO:0000250|UniProtKB:Q9R0K7, ECO:0000269|PubMed:15829536, ECO:0000269|PubMed:17234811, ECO:0000269|PubMed:25690014}。

组织特异性

Mainly expressed in brain cortex. Found in low levels in skeletal muscle, heart muscle, stomach, liver, kidney and lung. Isoforms containing segment B are found in brain cortex and at low levels in other tissues. Isoforms containing segments X and W are found at low levels in all tissues. Isoforms containing segment A and segment Z are found at low levels in skeletal muscle and heart muscle.

亚细胞定位

Cell membrane