Fig. 2.

An integrated view of receptor-initiated nuclear Ca²⁺ signals in cardiomyocyte. Different agonists can activate receptors located in the sarcolemma (1 and 3) or intracellular receptors (2). Pathway 1: Perinuclear receptors located in deep T-tubules can lead to PLC-dependent InsP₃ generation in peri/nuclear compartments. Pathway 2: Intracellular receptors can be activated by lipophilic ligands (steroid hormones) or endocytosed ligands, leading to PLC-dependent InsP₃ generation in peri/nuclear compartments. Pathway 3: Receptors located in peripheral sarcolemma lead to generation of InsP₃ and its diffusion into the nucleus triggers nuclear Ca²⁺ signals.