Worm Breeder's Gazette 16(4): 35 (October 1, 2000)

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

The C. elegans klp-14 encodes a novel BimC kinesin like protein that mediates chromosomal segregation during embryogenesis

M. Yusuf Ali1, Zeba K. Siddiqui2, Ayesha Shahjahan2, Shams T. Khan3, Eric J. Lambie4, Shahid S. Siddiqui5

1 CREST, Yokohama, Japan, and TUT, Toyohashi, Japan
2 Pharmacology Dept, Univ of Illinois, Chicago, IL 60607
3 Depot of Ecological Engineering, TUT, Toyohashi, Japan
4 Dept of Biology, Dartmouth College, Hanover, NH 03755
5 Pharmacology Dept, Univ of Illinois, Chicago, IL 60607, and Dept of Ecological Engineering, Toyohashi University of Technology, Toyohashi 441-8580, Japan

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manuscript unpublished).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