Plays an important role in cell protection against oxidative stress and in the regulation of redox-related calcium homeostasis. Regulates the calcium level of the ER by protecting the calcium pump ATP2A2 against the oxidoreductase ERO1A-mediated oxidative damage. Within the ER, ERO1A activity increases the concentration of H(2)O(2), which attacks the luminal thiols in ATP2A2 and thus leads to cysteinyl sulfenic acid formation (-SOH) and SEPN1 reduces the SOH back to free thiol (-SH), thus restor

Endoplasmic reticulum membrane

Congenital myopathy 3 with rigid spine

An autosomal recessive, slowly progressive muscular disorder apparent from birth or early childhood and characterized by hypotonia, proximal muscle weakness, poor axial muscle strength, scoliosis and neck weakness, and a variable degree of spinal rigidity. Most patients remain ambulatory. Early ventilatory insufficiency may lead to death by respiratory failure. Additional features may include facial muscle weakness, amyotrophy, joint contractures, distal hyperlaxity, pulmonary hypertension with secondary cardiac dysfunction, and insulin resistance in patients with a low BMI. Skeletal muscle biopsy typically shows multiminicores and other abnormal non-specific myopathic findings.