Krp1, a novel kelch related protein that is involved in pseudopod elongation in transformed cells.
We have previously shown that the transcription factor AP-1 regulates the expression of genes which allow neoplastically transformed rat fibroblasts to become invasive. Searches for further AP-1 target genes led to the identification of a gene encoding a novel rat kelch family member, named kelch related protein 1 (Krp1). Kelch family members are characterized by a series of repeats at their carboxyl terminus and a BTB/POZ domain near their amino terminus. Rat Krp1 has a primarily cytoplasmic localization, and a small fraction appears to accumulate and co-localize with F-actin at membrane ruffle-like structures in the tips of pseudopodia. Overexpression of Krp1 in transformed rat fibroblasts led to the formation of dramatically elongated pseudopodia, while expression of truncated Krp1 polypeptides resulted in a reduction in the length of pseudopodia. We propose that the transformation-specific expression of Krp1 is required for pseudopod elongation, which are structures that are required for cell motility and invasion.
Spence
H J
HJ
Beatson Institute for Cancer Research, Garscube Estate, Switchback Road, Bearsden, Glasgow, G61 1BD.
Johnston
I
I
Ewart
K
K
Buchanan
S J
SJ
Fitzgerald
U
U
Ozanne
B W
BW
D000199:Actins / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification*; D002471:Cell Transformation, Neoplastic; D003598:Cytoskeletal Proteins; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D016761:Oncogene Proteins v-fos / Q000235:genetics; D011554:Pseudopodia / Q000502:physiology*; D051381:Rats; D017386:Sequence Homology, Amino Acid; D015854:Up-Regulation; D018631:ras Proteins / Q000235:genetics
D000199:Actins; D002352:Carrier Proteins; D003598:Cytoskeletal Proteins; C586302:KLHL41 protein, human; C405542:Klhl41 protein, rat; D016761:Oncogene Proteins v-fos; D018631:ras Proteins