Schematic showing how ck2β deletion induces a defect in proplatelet formation with a premature MK fragmentation and how it impairs α-thrombin/PAR-1 and collagen/glycoprotein VI (GPVI) signaling. (A) Megakaryocyte maturation in bone marrow and platelet release into blood circulation in (i) presence or (ii) absence of CK2β. (B) End-binding protein 3 (EB3)-dependent stabilization of tubulin polymerization in (i) presence or (ii) absence of CK2β. (C) Regulation of intracellular Ca²⁺ release during Ca²⁺-dependent platelet activation in (i) presence or (ii) absence of CK2β. CLASPs, cytoplasmic linker associated proteins; DMS, demarcation membrane system; ER, endoplasmic reticulum; FcR, Fc receptor; Gαq/11, Gq protein; GDP, guanosine diphosphate; GTP, guanosine triphosphate; ITAM, immunoreceptor tyrosine-based activation motif; p, phosphorylated; PIP2, phosphatidyl inositol diphosphate; PLC, phospholipase; SH3, sarc homology 3 domain; SYK, spleen tyrosine kinase; Y, tyrosine.