Updated publication reference for PubMed record(s): 32795391. Coordination of membrane-related processes inside the cells is facilitated by proteins regulating multiple vesicular trafficking pathways. Bone morphogenetic protein 2-inducible kinase (BMP2K) is a poorly studied ubiquitous protein with the highest expression in the erythroid lineage. We hypothesized that this kinase, potentially implicated in endocytosis and autophagy, could integrate various trafficking routes. By proximity biotinylation (BioID), we revealed differential association of two BMP2K splicing variants with regulators of clathrin-mediated endocytosis (CME) and with components of early secretory pathway (ESP). We found the longer variant (BMP2K-L) to interact with markers of clathrin-coated pits, REPS1 and phosphorylated μ2 adaptin, and the shorter variant (BMP2K-S) to associate with early secretory compartments positive for ARFGAP1 and SEC16A proteins. Splicing variant-specific RNAi approach in K562 erythroleukemia cells showed that BMP2K-L controls μ2 phosphorylation while BMP2K-S post-transcriptionally maintains SEC16A protein levels. Depleting all BMP2K splicing variants promoted autophagic degradation via a functional crosstalk with SEC16A, enhanced transferrin endocytosis, and erythroid differentiation. We propose that, owing to alternative splicing, BMP2K gene products restrict erythroid differentiation coordinating endocytosis and SEC16A-dependent autophagy.