Receptor for thrombopoietin that acts as a primary regulator of megakaryopoiesis and platelet production. May represent a regulatory molecule specific for TPO-R-dependent immune responses. Acts as an inhibitor of thrombopoietin signaling by promoting protein down-regulation of full-length isoform Mpl-fl. Homodimer. Interacts with ATXN2L. Expression in the bone marrow displays diurnal rhythmicity (a circadian rhythm that is synchronized with the day/night cycle). The WSXWS motif appears to be necessary for proper protein folding and thereby efficient intracellular transport and cell-surface receptor binding. The box 1 motif is required for JAK interaction and/or activation. Ubiquitination at Lys-544 and Lys-564 targets MPL for degradation by both the lysosomal and proteasomal pathways. The E3 ubiquitin-protein ligase CBL significantly contributes to this ubiquitination (By similarity). Rbm15 regulates the production of isoform Mpl-tr. Belongs to the type I cytokine receptor family. Type 1 subfamily.