Small integral membrane protein 21 (SMIM21)

Small integral membrane protein 21 (SMIM21), also known as C18orf62, is a predicted single-pass membrane protein localized to cellular membranes, including those of endolysosomal compartments[2][4]. While the exact function of SMIM21 has not been directly elucidated, it is hypothesized—by analogy to related proteins involved in the endosomal sorting complexes required for transport (ESCRT) pathway—to play a role in membrane protein trafficking and degradation critical for cellular homeostasis[2]. Potential functional roles have been proposed in processes such as endolysosomal degradation in cardiac cells (protecting against maladaptive cardiac remodeling) and maintaining synaptic integrity in neurons (preventing cognitive dysfunction), though these inferences are based on similarities to ESCRT-III proteins like CHMP4C and Snf7-3 rather than direct experimental evidence[2]. Currently, SMIM21 is not recognized as a therapeutic target, and there are no known drugs, established biomarkers, or described safety concerns associated with this protein[2][4].

Other names

C18orf62SMI21_HUMAN