P17119 · KAR3_YEAST
- ProteinKinesin-like protein KAR3
- GeneKAR3
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids729 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Minus end-directed microtubule (MT) motor involved in spindle midzone assembly, poleward transport of newly captured kinetochores along the lateral side of MTs, karyogamy (nuclear fusion) during mating, and with an essential function in meiosis I (PubMed:11387196, PubMed:11729143, PubMed:17382884, PubMed:17620411, PubMed:22734002, PubMed:25313961, PubMed:7912193, PubMed:8106549, PubMed:9334348, PubMed:9859995).
Functions together with the accessory proteins CIK1 or VIK1 (PubMed:10087265, PubMed:11729143, PubMed:15846338, PubMed:17382884, PubMed:22734002, PubMed:25313961).
Drives the poleward transport of newly captured kinetochores along the lateral side of MTs, both during S-phase and during M-phase (PubMed:15846338, PubMed:17620411, PubMed:18079178).
To contribute to spindle midzone assembly during mitotic metaphase, the nuclear KAR3-CIK1 motor cross-links anti-parallel microtubules to align them on the spindle axis; as the motor travels polewards splayed microtubules are pulled into alignment (PubMed:25313961).
During the karyogamy (nuclear fusion) step of mating, KAR3-CIK1 cross-links antiparallel cytoplasmic microtubules emanating from the spindle pole bodies of mating partners; the motor activity of KAR3 creates the force that pulls the nuclei together by sliding cross-linked microtubules past one another (PubMed:2138512, PubMed:8106549).
KAR3-CIK1 promotes microtubule shortening predominantly from the microtubule plus-end (PubMed:17382884).
Together with cytoplasmic VIK1, may act to stabilize microtubules (PubMed:17382884).
Requires accessory protein VIK1 for spindle pole body localization and to allow the CIN8 and KIP1 motors to generate outwardly directed spindle forces (PubMed:11729143, PubMed:2138512, PubMed:7912193, PubMed:8224825).
Essential during meiosis I (PubMed:9334348).
The ATPase activity is stimulated by microtubule-binding (PubMed:11387196, PubMed:22734002, PubMed:9859995).
Functions together with the accessory proteins CIK1 or VIK1 (PubMed:10087265, PubMed:11729143, PubMed:15846338, PubMed:17382884, PubMed:22734002, PubMed:25313961).
Drives the poleward transport of newly captured kinetochores along the lateral side of MTs, both during S-phase and during M-phase (PubMed:15846338, PubMed:17620411, PubMed:18079178).
To contribute to spindle midzone assembly during mitotic metaphase, the nuclear KAR3-CIK1 motor cross-links anti-parallel microtubules to align them on the spindle axis; as the motor travels polewards splayed microtubules are pulled into alignment (PubMed:25313961).
During the karyogamy (nuclear fusion) step of mating, KAR3-CIK1 cross-links antiparallel cytoplasmic microtubules emanating from the spindle pole bodies of mating partners; the motor activity of KAR3 creates the force that pulls the nuclei together by sliding cross-linked microtubules past one another (PubMed:2138512, PubMed:8106549).
KAR3-CIK1 promotes microtubule shortening predominantly from the microtubule plus-end (PubMed:17382884).
Together with cytoplasmic VIK1, may act to stabilize microtubules (PubMed:17382884).
Requires accessory protein VIK1 for spindle pole body localization and to allow the CIN8 and KIP1 motors to generate outwardly directed spindle forces (PubMed:11729143, PubMed:2138512, PubMed:7912193, PubMed:8224825).
Essential during meiosis I (PubMed:9334348).
The ATPase activity is stimulated by microtubule-binding (PubMed:11387196, PubMed:22734002, PubMed:9859995).
Miscellaneous
KAR3 contains two globular domains separated by an alpha-helical coiled coil. The N-terminal portion of KAR3 contains a microtubule association domain distinct from the kinesin-like C-terminal domain.
Present with 3250 molecules/cell in log phase SD medium.
Catalytic activity
- ATP + H2O = ADP + H+ + phosphateThis reaction proceeds in the forward direction.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
12.2 μM | MgATP | |||||
18.6 μM | MgATP in complex with CIK1 | |||||
15 μM | MgATP in complex with VIK1 |
kcat is 0.49 sec-1 with MgATP as substrate (PubMed:17382884).
kcat is 2.8 sec-1 with MgATP as substrate in complex with CIK1 (PubMed:17382884).
kcat is 3.7 sec-1 with MgATP as substrate in complex with VIK1 (PubMed:17382884).
kcat is 2.8 sec-1 with MgATP as substrate in complex with CIK1 (PubMed:17382884).
kcat is 3.7 sec-1 with MgATP as substrate in complex with VIK1 (PubMed:17382884).
Features
Showing features for binding site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Binding site | 386 | ATP (UniProtKB | ChEBI) | ||||
Sequence: N | ||||||
Binding site | 388 | ATP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 392 | ATP (UniProtKB | ChEBI) | ||||
Sequence: R | ||||||
Binding site | 454 | ATP (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 477 | ATP (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 478 | ATP (UniProtKB | ChEBI) | ||||
Sequence: S | ||||||
Binding site | 479 | ATP (UniProtKB | ChEBI) | ||||
Sequence: G | ||||||
Binding site | 480 | ATP (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 481 | ATP (UniProtKB | ChEBI) | ||||
Sequence: T | ||||||
Binding site | 482 | ATP (UniProtKB | ChEBI) | ||||
Sequence: F | ||||||
Binding site | 554 | ATP (UniProtKB | ChEBI) | ||||
Sequence: E | ||||||
Binding site | 579 | ATP (UniProtKB | ChEBI) | ||||
Sequence: K | ||||||
Binding site | 694 | ATP (UniProtKB | ChEBI) | ||||
Sequence: T |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | chromosome | |
Cellular Component | cytoplasmic microtubule | |
Cellular Component | microtubule | |
Cellular Component | nucleus | |
Cellular Component | spindle pole | |
Cellular Component | spindle pole body | |
Molecular Function | ATP binding | |
Molecular Function | ATP hydrolysis activity | |
Molecular Function | isomerase activity | |
Molecular Function | microtubule binding | |
Molecular Function | minus-end-directed microtubule motor activity | |
Biological Process | cell division | |
Biological Process | karyogamy involved in conjugation with cellular fusion | |
Biological Process | meiotic cell cycle | |
Biological Process | microtubule bundle formation involved in mitotic spindle midzone assembly | |
Biological Process | mitotic cell cycle | |
Biological Process | mitotic sister chromatid cohesion | |
Biological Process | nuclear migration involved in conjugation with cellular fusion | |
Biological Process | protein transport along microtubule to mitotic spindle pole body | |
Biological Process | regulation of mitotic spindle organization |
Keywords
- Molecular function
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameKinesin-like protein KAR3
- EC number
- Alternative names
Gene names
Organism names
- Strains
- Taxonomic lineageEukaryota > Fungi > Dikarya > Ascomycota > Saccharomycotina > Saccharomycetes > Saccharomycetales > Saccharomycetaceae > Saccharomyces
Accessions
- Primary accessionP17119
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Keywords
- Cellular component
Phenotypes & Variants
Disruption phenotype
Short mitotic metaphase spindles with splayed microtubules (MTs) increasing spindle width (PubMed:25313961).
Disrupts the poleward movement of kinetochores on MTs; abolishes poleward sliding along the lateral side of MTs and increases end-on pulling (PubMed:15846338, PubMed:17620411).
During karyogamy, (the mating step where nuclei fuse), abolishes the formation of a MT bridge between the two nuclei thereby leading to a failure in nuclear fusion (PubMed:8106549).
Abnormal meiosis I; cells do not progress past prophase I, interhomolog recombination is abnormal and the organization of MTs is abnormal (PubMed:9334348).
Disrupts the poleward movement of kinetochores on MTs; abolishes poleward sliding along the lateral side of MTs and increases end-on pulling (PubMed:15846338, PubMed:17620411).
During karyogamy, (the mating step where nuclei fuse), abolishes the formation of a MT bridge between the two nuclei thereby leading to a failure in nuclear fusion (PubMed:8106549).
Abnormal meiosis I; cells do not progress past prophase I, interhomolog recombination is abnormal and the organization of MTs is abnormal (PubMed:9334348).
Features
Showing features for natural variant, mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | 378 | in KAR3-894 | ||||
Sequence: N → K | ||||||
Natural variant | 462 | in KAR3-891 | ||||
Sequence: S → L | ||||||
Mutagenesis | 479 | Poisons nuclear fusion. | ||||
Sequence: G → E | ||||||
Natural variant | 521 | in KAR3-893 | ||||
Sequence: E → D | ||||||
Natural variant | 550 | in KAR3-899 | ||||
Sequence: R → S | ||||||
Natural variant | 558 | in KAR3-8912 | ||||
Sequence: T → A | ||||||
Mutagenesis | 598 | Disrupts microtubule binding. Abolishes microtubule-activated ATPase activity. | ||||
Sequence: R → A | ||||||
Mutagenesis | 631 | Increases strength of microtubule binding. Abolishes microtubule-activated ATPase activity. | ||||
Sequence: E → A | ||||||
Mutagenesis | 632 | Decreases microtubule-activated ATPase activity. | ||||
Sequence: R → A | ||||||
Natural variant | 650 | in KAR3-898 | ||||
Sequence: N → K | ||||||
Mutagenesis | 650 | Increases strength of microtubule binding. Prevents release of ADP upon microtubule-binding. | ||||
Sequence: N → K | ||||||
Natural variant | 659 | in KAR3-897 | ||||
Sequence: V → L |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 19 variants from UniProt as well as other sources including ClinVar and dbSNP.
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000125391 | 1-729 | Kinesin-like protein KAR3 | |||
Sequence: MESLPRTPTKGRSTQHLSTPSPKNDILAMNGHKRRNTTTPPPKHTLLKPQRTDIHRHSLASQSRISMSPNRELLKNYKGTANLIYGNQKSNSGVTSFYKENVNELNRTQAILFEKKATLDLLKDELTETKEKINAVNLKFETLREEKIKIEQQLNLKNNELISIKEEFLSKKQFMNEGHEIHLKQLAASNKKELKQMENEYKTKIEKLKFMKIKQFENERASLLDKIEEVRNKITMNPSTLQEMLNDVEQKHMLEKEEWLTEYQSQWKKDIELNNKHMQEIESIKKEIENTLKPELAEKKKLLTEKRNAYEAIKVKVKEKEEETTRLRDEVALKQKTNLETLEKIKELEEYIKDTELGMKELNEILIKEETVRRTLHNELQELRGNIRVYCRIRPALKNLENSDTSLINVNEFDDNSGVQSMEVTKIQNTAQVHEFKFDKIFDQQDTNVDVFKEVGQLVQSSLDGYNVCIFAYGQTGSGKTFTMLNPGDGIIPSTISHIFNWINKLKTKGWDYKVNCEFIEIYNENIVDLLRSDNNNKEDTSIGLKHEIRHDQETKTTTITNVTSCKLESEEMVEIILKKANKLRSTASTASNEHSSRSHSIFIIHLSGSNAKTGAHSYGTLNLVDLAGSERINVSQVVGDRLRETQNINKSLSCLGDVIHALGQPDSTKRHIPFRNSKLTYLLQYSLTGDSKTLMFVNISPSSSHINETLNSLRFASKVNSTRLVSRK |
Proteomic databases
PTM databases
Expression
Induction
By alpha factor.
Interaction
Subunit
Interacts with CIK1; the interaction is direct (PubMed:10087265, PubMed:17382884, PubMed:8106549).
Interacts with VIK1; the interaction is direct (PubMed:10087265, PubMed:17382884).
Interacts with VIK1; the interaction is direct (PubMed:10087265, PubMed:17382884).
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | P17119 | SMC1 P32908 | 4 | EBI-9499, EBI-17402 | |
BINARY | P17119 | VIK1 Q12045 | 4 | EBI-9499, EBI-38784 |
Protein-protein interaction databases
Miscellaneous
Structure
Family & Domains
Features
Showing features for compositional bias, region, coiled coil, domain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 1-45 | Polar residues | ||||
Sequence: MESLPRTPTKGRSTQHLSTPSPKNDILAMNGHKRRNTTTPPPKHT | ||||||
Region | 1-48 | Disordered | ||||
Sequence: MESLPRTPTKGRSTQHLSTPSPKNDILAMNGHKRRNTTTPPPKHTLLK | ||||||
Region | 1-109 | Globular | ||||
Sequence: MESLPRTPTKGRSTQHLSTPSPKNDILAMNGHKRRNTTTPPPKHTLLKPQRTDIHRHSLASQSRISMSPNRELLKNYKGTANLIYGNQKSNSGVTSFYKENVNELNRTQ | ||||||
Coiled coil | 110-357 | |||||
Sequence: AILFEKKATLDLLKDELTETKEKINAVNLKFETLREEKIKIEQQLNLKNNELISIKEEFLSKKQFMNEGHEIHLKQLAASNKKELKQMENEYKTKIEKLKFMKIKQFENERASLLDKIEEVRNKITMNPSTLQEMLNDVEQKHMLEKEEWLTEYQSQWKKDIELNNKHMQEIESIKKEIENTLKPELAEKKKLLTEKRNAYEAIKVKVKEKEEETTRLRDEVALKQKTNLETLEKIKELEEYIKDTEL | ||||||
Domain | 386-723 | Kinesin motor | ||||
Sequence: NIRVYCRIRPALKNLENSDTSLINVNEFDDNSGVQSMEVTKIQNTAQVHEFKFDKIFDQQDTNVDVFKEVGQLVQSSLDGYNVCIFAYGQTGSGKTFTMLNPGDGIIPSTISHIFNWINKLKTKGWDYKVNCEFIEIYNENIVDLLRSDNNNKEDTSIGLKHEIRHDQETKTTTITNVTSCKLESEEMVEIILKKANKLRSTASTASNEHSSRSHSIFIIHLSGSNAKTGAHSYGTLNLVDLAGSERINVSQVVGDRLRETQNINKSLSCLGDVIHALGQPDSTKRHIPFRNSKLTYLLQYSLTGDSKTLMFVNISPSSSHINETLNSLRFASKVNST |
Sequence similarities
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length729
- Mass (Da)84,004
- Last updated1990-08-01 v1
- ChecksumBAEF98BC783ABDB9
Features
Showing features for compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 1-45 | Polar residues | ||||
Sequence: MESLPRTPTKGRSTQHLSTPSPKNDILAMNGHKRRNTTTPPPKHT |
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
M31719 EMBL· GenBank· DDBJ | AAA34715.1 EMBL· GenBank· DDBJ | mRNA | ||
U40829 EMBL· GenBank· DDBJ | AAB68281.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BK006949 EMBL· GenBank· DDBJ | DAA11555.1 EMBL· GenBank· DDBJ | Genomic DNA |