High impact information on KIP1

• Deletion of kinesin-related KAR3 partially suppressed the phenotypes associated with loss of Cin8p/Kip1p function [1].
• We identified two new Saccharomyces cerevisiae kinesin-related genes, KIP1 and KIP2, using polymerase chain reaction primers corresponding to highly conserved regions of the kinesin motor domain [2].
• KIP1 and CIN8 are functionally redundant: double mutants arrested in mitosis whereas the single mutants did not [2].
• Two Saccharomyces cerevisiae genes, CIN8 and KIP1 (a.k.a. CIN9), were identified by their requirement for normal chromosome segregation [3].
• Moreover, kip1 kip2 double mutants and a triple mutant with kinesin-related kar3 had no synthetic phenotype [2].

Biological context of KIP1

• The kinesin-related products of the CIN8 and KIP1 genes of Saccharomyces cerevisiae redundantly perform an essential function in mitosis [4].
• These mutations also suppressed the inviability associated with the cin8-delta kip1-delta genotype, a property not shared by a deletion of KAR3 [4].
• Microtubule depolymerization may also be the mechanism by which Kar3p acts in opposition to the anaphase B motors Cin8p and Kip1p [5].
• KIP1 is present in a single copy in the genome, and is expressed predominantly in pollen with a similar temporal pattern to PRK1 [6].
• The amino acid sequence of KIP1 deduced from full-length cDNA contains an EF-hand Ca(2+)-binding motif and nine predicted coiled-coil regions [6].

Anatomical context of KIP1

• The microtubule organizing centers of arrested cells were duplicated but unseparated, indicating that KIP1 or CIN8 is required for mitotic spindle assembly [2].
• Since ectopic expression of proteolysis-resistant Cin8, Kip1 or Ase1 is sufficient for SPB separation even in the absence of Cdc28-Clb activity, we suggest that stabilization of these mechanical force-generating proteins is the predominant role of Cdc28-Clb in centrosome separation [7].
• These include genes whose products act in two spindle motor pathways that overlap in function with Cin8p, the kinesin-related Kip1p pathway and the cytoplasmic dynein pathway [8].

Associations of KIP1 with chemical compounds

• Conditionally lethal double mutants containing the temperature sensitive allele cin8-3 in a background deletion of either kip1 or dyn1 grew normally at the restrictive temperature when osmolytes such as sorbitol were added to the medium [9].

Regulatory relationships of KIP1

• Loss of function of Saccharomyces cerevisiae kinesin-related CIN8 and KIP1 is suppressed by KAR3 motor domain mutations [4].

Other interactions of KIP1

• We have selected mutations that suppress the temperature-sensitivity of a cin8-temperature-sensitive kip1-delta strain [4].
• Our findings suggest that despite an antagonistic relationship between Cin8p/Kip1p and Kar3p, aspects of their mitotic roles may be similar [4].
• Sequencing and functional analysis of a 32,560 bp segment on the left arm of yeast chromosome II. Identification of 26 open reading frames, including the KIP1 and SEC17 genes [10].
• Finally, overexpression of the KIP1 gene in vivo in Saccharomyces cerevisiae, like overexpression of the related SIC1 gene, rescues the cell cycle-related phenotype of a sic1Delta strain [11].

Analytical, diagnostic and therapeutic context of KIP1

• In situ hybridization showed that PRK1 and KIP1 transcripts were localized in the cytoplasm of pollen [6].
• The yeast two-hybrid assay and affinity chromatography showed that KIP1 interacts with itself to form a dimer or higher multimer [6].
• Electron microscopy of rotary shadowed Kip1p molecules revealed two globular domains 14 nm in diameter connected by a 73-nm long stalk [12].

References