Tmem14c, an inner mitochondrial membrane protein enriched in vertebrate hematopoietic tissues, is essential for facilitating the import of protoporphyrinogen IX into the mitochondrial matrix. This function is crucial for heme synthesis in the heme biosynthesis pathway, which is vital for hemoglobin production and erythropoiesis [1,3]. Genetic models, such as knockout mouse models, are valuable for studying Tmem14c's role in these processes.

In mice, Tmem14c deficiency leads to porphyrin accumulation in the fetal liver, erythroid maturation arrest, and embryonic lethality due to profound anemia. Protoporphyrin IX synthesis in Tmem14c-deficient erythroid cells is blocked, causing an accumulation of porphyrin precursors [1]. In an induced pluripotent stem cell model of SF3B1-mutant myelodysplastic syndrome, mutant SF3B1 induces missplicing of Tmem14c, reducing its protein expression. Functional rescue of Tmem14c markedly decreases the formation of ring sideroblasts, indicating its role in preventing abnormal iron sequestration in mitochondria [2].

In conclusion, Tmem14c is essential for erythroid mitochondrial heme metabolism. Its deficiency in KO mouse models reveals its critical role in preventing congenital anemias and disorders like myelodysplastic syndrome related to abnormal heme metabolism and iron sequestration. The study of Tmem14c through these models helps to understand the mechanisms underlying erythropoiesis and associated diseases.