Characterization of a novel splicing variant of KLHL5, a member of the kelch protein family.

The kelch-repeat protein family is a recently found new kind of actin-binding protein. It is characterized by tandemly arranged motifs of about 50 amino acids. Previous study showed that most members of the kelch-repeat family were cytoskeletal proteins implicated in various cellular processes, such as actin cytoskeleton interaction, cytoplasmic sequestration of transcription factors and cell morphology. And some of the family members play important roles in tissue development, such as human ENC-1, NRP/B, etc. Another characteristic of the kelch family is that most members have another conserved BTB domain at the extreme amino terminus. The BTB domain is also found at the N-terminus of 5-10% of zinc-finger transcription factor types and is a conserved protein-protein interaction motif. During the large-scale sequencing analysis of a human fetal brain cDNA library we found a novel kelch-like protein gene 5, KLHL5, KLHL5 has high identity with Drosophila kelch protein and many other family members. Here we report a novel splicing variants of KLHL5, named KLHL5b and the expression pattern of KLHL5b in many tissues.