The study investigates the role of calcium ([Ca²⁺]) in regulating macroautophagy, a lysosomal pathway involved in cellular homeostasis. The authors demonstrate that an increase in cytosolic [Ca²⁺]c is a potent inducer of macroautophagy, as evidenced by the accumulation of autophagosomes and the degradation of long-lived proteins. This induction is mediated by Ca²⁺/calmodulin-dependent kinase kinase-β (CaMKK-β) and AMP-activated protein kinase (AMPK), and is inhibited by Bcl-2, a protein that localizes to the endoplasmic reticulum (ER). The ER-located Bcl-2 inhibits autophagy by lowering the ER [Ca²⁺]ER and reducing agonist-induced Ca²⁺ fluxes. The findings suggest that an increase in cytosolic [Ca²⁺]c serves as a potent inducer of macroautophagy and that ER-located Bcl-2 plays a crucial role in the anti-autophagy action by regulating Ca²⁺ homeostasis in the ER. These results provide new insights into the molecular mechanisms underlying the control of macroautophagy and highlight the importance of Ca²⁺ and Bcl-2 in cellular homeostasis and cell survival.The study investigates the role of calcium ([Ca²⁺]) in regulating macroautophagy, a lysosomal pathway involved in cellular homeostasis. The authors demonstrate that an increase in cytosolic [Ca²⁺]c is a potent inducer of macroautophagy, as evidenced by the accumulation of autophagosomes and the degradation of long-lived proteins. This induction is mediated by Ca²⁺/calmodulin-dependent kinase kinase-β (CaMKK-β) and AMP-activated protein kinase (AMPK), and is inhibited by Bcl-2, a protein that localizes to the endoplasmic reticulum (ER). The ER-located Bcl-2 inhibits autophagy by lowering the ER [Ca²⁺]ER and reducing agonist-induced Ca²⁺ fluxes. The findings suggest that an increase in cytosolic [Ca²⁺]c serves as a potent inducer of macroautophagy and that ER-located Bcl-2 plays a crucial role in the anti-autophagy action by regulating Ca²⁺ homeostasis in the ER. These results provide new insights into the molecular mechanisms underlying the control of macroautophagy and highlight the importance of Ca²⁺ and Bcl-2 in cellular homeostasis and cell survival.