The RING-type zinc finger motif is present in a number of viral and eukaryotic proteins and is made of a conserved cysteine-rich domain that is able to bind two zinc atoms. Proteins that contain this conserved domain are generally involved in the ubiquitination pathway of protein degradation. RNF141 (ring finger protein 141), also known as ZFP26 or ZNF230, is a 230 amino acid protein that contains one RING-type zinc finger. Expressed as two isoforms (isoform 1 and isoform 2) due to alternative splicing events, RNF141 is thought to function as a transcription factor during spermatogenesis. While isoform 2 is expressed in brain, heart, pancreas, kidney and skeletal muscle, isoform 1 is expressed primarily in testis, suggesting that isoform 1 functions during spermatogenesis. In addition, RNF141 is not expressed in azoospermic (infertile) men, further implicating an important role for RNF141 in testis development and male fertility.