Identification and phylogenetic analysis of Dictyostelium discoideum kinesin proteins.
BACKGROUND
Kinesins constitute a large superfamily of motor proteins in eukaryotic cells. They perform diverse tasks such as vesicle and organelle transport and chromosomal segregation in a microtubule- and ATP-dependent manner. In recent years, the genomes of a number of eukaryotic organisms have been completely sequenced. Subsequent studies revealed and classified the full set of members of the kinesin superfamily expressed by these organisms. For Dictyostelium discoideum, only five kinesin superfamily proteins (Kif's) have already been reported.


RESULTS
Here, we report the identification of thirteen kinesin genes exploiting the information from the raw shotgun reads of the Dictyostelium discoideum genome project. A phylogenetic tree of 390 kinesin motor domain sequences was built, grouping the Dictyostelium kinesins into nine subfamilies. According to known cellular functions or strong homologies to kinesins of other organisms, four of the Dictyostelium kinesins are involved in organelle transport, six are implicated in cell division processes, two are predicted to perform multiple functions, and one kinesin may be the founder of a new subclass.


CONCLUSIONS
This analysis of the Dictyostelium genome led to the identification of eight new kinesin motor proteins. According to an exhaustive phylogenetic comparison, Dictyostelium contains the same subset of kinesins that higher eukaryotes need to perform mitosis. Some of the kinesins are implicated in intracellular traffic and a small number have unpredictable functions.
Kollmar
Martin
M
Abteilung NMR basierte Strukturbiologie, Max-Planck-Institut für Biophysikalische Chemie, Am Fabetaberg 11, D-37077 Göttingen, Germany. mako@nmr.mpibpc.mpg.de
Glöckner
Gernot
G
D000818:Animals; D004023:Dictyostelium / Q000235:genetics*; D016547:Kinesins / Q000145:classification* / Q000235:genetics / Q000502:physiology; D020409:Molecular Motor Proteins / Q000145:classification / Q000235:genetics; D010802:Phylogeny; D015800:Protozoan Proteins / Q000145:classification* / Q000235:genetics / Q000502:physiology; D009626:Terminology as Topic
D020409:Molecular Motor Proteins; D015800:Protozoan Proteins; D016547:Kinesins