Kelch Like Protein 4 (KLHL4)

The KLHL4 transcript represents an approximately 3.6-kb mRNA and encodes a 718-amino acid protein. PCR analysis demonstrated alternative use of exons 11a and 11d, with the exon 11d transcript encoding a 719-amino acid protein. KLHL4 contains 6 tandem repeats (Kelch repeats) at the C terminus and a POZ/BTB protein-binding domain toward the N terminus, characteristic of Kelch family members. The POZ/BTB domain is a 120-amino acid motif generally located in the N terminus of actin-binding proteins and believed to be important in protein-protein interactions, allowing homomeric or heteromeric dimerization. Kelch-like proteins usually have distinct N-terminal ends, but KLHL4 shows 88% similarity over the first 25 amino acids with KLHL1.