JOSD1 Human

Josephin Domain Containing 1 (JOSD1) is a protein encoded by the JOSD1 gene in humans. This protein is characterized by the presence of a Josephin domain, a type of cysteine protease domain that plays a crucial role in the deubiquitination process. Deubiquitination is the removal of ubiquitin from proteins, a process essential for various cellular functions, including protein degradation, signal transduction, and cell cycle regulation .

JOSD1 is a protein coding gene that produces a polypeptide chain containing 225 amino acids with a molecular mass of approximately 25.6 kDa . The protein is often produced in recombinant form with an N-terminal His-tag to facilitate purification and study. The Josephin domain within JOSD1 is responsible for its deubiquitinase activity, which allows it to cleave ubiquitin from other proteins .

JOSD1 has been implicated in various cellular processes. It is known to deubiquitinate monoubiquitinated probes in vitro and cleave both ‘Lys-63’-linked and ‘Lys-48’-linked poly-ubiquitin chains . This activity suggests that JOSD1 may play a role in regulating protein stability and function. Additionally, JOSD1 has been shown to increase macropinocytosis and suppress clathrin- and caveolae-mediated endocytosis, thereby enhancing membrane dynamics and cell motility independently of its catalytic activity .

Mutations or dysregulation of JOSD1 have been associated with various diseases, including diabetic retinopathy and microvascular complications of diabetes . The protein’s role in deubiquitination and cellular dynamics makes it a potential target for therapeutic interventions in these conditions.