Kinesin motor proteins are microtubule based ATPases which orchestrate intracellular vesicular traffic. We have defined a superfamily of kinesin like proteins
klp-1 to
klp-20 in C. elegans, and examined their structure and cellular function. RNAi assay and in situ hybridization experiments using different kinesin cDNA clones has revealed that majority of kinesins function in embryonic development (Ali et al., 2000 a, b. c). A 3.0-kb cDNA clone has been isolated and sequenced that encodes a full-length
klp-14 gene. The encoded CEKLP-14 is an ortholog of the BimC kinesin in C. elegans. Genome sequencing has placed the cosmid clone (F23B12.8) encoding
klp-14 on chromosome V, between the
ceh-35 and stP-6 loci. Deduced amino acid sequence, based on the cDNA and genomic sequence analysis shows that the
klp-14 gene encoded CEKLP-14 is 958 residues long. Secondary structure analysis suggests that KLP-14 harbor an amino terminus globular motor domain of 390 aa, which is linked, with an alpha helical rod domain of about 400 aa, and a carboxyl terminal globular domain of 168 residues. The RNA in situ hybridization experiment, using a CEKLP-14 specific cDNA probe, reveals that the
klp-14 mRNA is indeed expressed at a high levels during C. elegans embryogenesis. Support of this notion comes from the RNAi experiments where a
klp-14 double stranded RNA interference assay results in the arrest of embryonic development and abnormal positioning of spindles, and chromosomes in early cell divisions (Ali et al., 2000, manuscript unpublished). Thus, CEKLP-14 may also mediate similar cellular functions in mitotic spindle movement, as is known for other members of the BimC family. Members of the BimC group of kinesin subfamily, implicated in spindle assembly and function, have been found across diverse species, from fungi to humans (Roof et al., 1992; Moore and Endow, 1996). It is worth examining how do mitotic spindles bundle up and slide during different stages of the cell divisions. We are examining the KLP-14 expression pattern using the specific antiserum during nematode embryonic and post-embryonic development. Recently, a UV induced mutation
dx88 that maps left to the
daf-21, in the region of
klp-14, shows embryonic arrest phenotype that is highly reminiscent of
klp-14 RNAi phenotype arrested embryos. Experiments are in progress to determine whether
dx88 is indeed an allele of the
klp-14 kinesin gene. Further characterization of the putative
klp-14 mutant will shed light on the role of
klp-14 in embryonic development and chromosome movement. We thank support from Monbusho, Japan, and NIH to SSS