NBL1/YHR199C-A Summary Help

Standard Name NBL1 1
Systematic Name YHR199C-A
Feature Type ORF, Verified
Description Subunit of the conserved chromosomal passenger complex (CPC); complex regulates mitotic chromosome segregation; not required for the kinase activity of the complex; mediates the interaction of Sli15p and Bir1p; other complex members are Ipl1p, Sli15p, and Bir1p (1 and see Summary Paragraph)
Name Description N-terminal-Borealin Like protein 1
Chromosomal Location
ChrVIII:498859 to 498571 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Gene Ontology Annotations All NBL1 GO evidence and references
  View Computational GO annotations for NBL1
Molecular Function
Manually curated
Biological Process
Manually curated
Cellular Component
Manually curated
Regulators 6 genes
Classical genetics
12 total interaction(s) for 4 unique genes/features.
Physical Interactions
  • Affinity Capture-MS: 5
  • Affinity Capture-Western: 3
  • Two-hybrid: 3

Genetic Interactions
  • Synthetic Growth Defect: 1

Length (a.a.) 73
Molecular Weight (Da) 8,547
Isoelectric Point (pI) 5.32
Phosphorylation PhosphoGRID | PhosphoPep Database
sequence information
ChrVIII:498859 to 498571 | ORF Map | GBrowse
Note: this feature is encoded on the Crick strand.
Last Update Coordinates: 2005-11-07 | Sequence: 2004-02-20
Subfeature details
Most Recent Updates
Coordinates Sequence
CDS 1..73 498859..498787 2005-11-07 2004-02-20
Intron 74..140 498786..498720 2005-11-07 2004-02-20
CDS 141..289 498719..498571 2005-11-07 2004-02-20
Retrieve sequences
Analyze Sequence
S288C only
S288C vs. other species
S288C vs. other strains
External Links All Associated Seq | Entrez Gene | Entrez RefSeq Protein | MIPS | Search all NCBI (Entrez) | UniProtKB
Retired NameMCL1
Primary SGDIDS000029704

The Aurora kinase complex (also called the chromosomal passenger complex, CPC) is an essential regulator of chromosome segregation, spindle checkpoint, and cytokinesis (reviewed in 2). The four members of the Aurora kinase complex are conserved from yeast to man. Ipl1p/Aurora B, a Ser/Thr protein kinase, is the enzymatic component of the complex (3, 4, 5, 6, 7). The other three complex members, Sli15p/INCENP (inner centromere protein) (8, 9, 10), Bir1p/Survivin (11, 5, 6, 7, 12, 13, 14, 15) and Nbl1p/Borealin (1), are all essential genes in S. cerevisiae and are thought to play roles in Ipl1p localization, stabilization and/or regulation. Bir1p contains three baculovirus IAP repeat domains, a protein motif which is usually found in inhibitor-of-apoptosis proteins (16), and Bir1p appears to play independent roles in chromosome stability and apoptosis (17 and reviewed in 18).

In S. cerevisiae, Ipl1p function is specifically required at many distinct locations and events during cell division (reviewed in 19, 20, 21, 2). Ipl1p localizes to kinetochores from G1 to metaphase and to the spindle after metaphase (22). During chromosome segregation, Aurora kinase ensures chromosome bi-orientation by promoting turnover of connections between kinetochores and spindle pole bodies until the movement of sister kinetochores toward opposite spindle poles creates tension (23, 24, 6, 25, reviewed in 26). If tension defects arise, Aurora kinase activity creates unattached kinetochores and activates the spindle assembly checkpoint (27, 28, 29). Ipl1p relocalizes to the spindle midzone in late anaphase (22), where it ensures that cytokinesis completes only after all chromosomes have migrated to the poles (30, 31). Ipl1p is also required for mitotic spindle disassembly (22, 32, 33, 34), and during this process Ipl1p localizes to the plus ends of the depolymerizing spindle microtubules (22). The dynamic localization of the Aurora kinase complex is a carefully regulated process. For example, it has been demonstrated that movement of the complex from the kinetochores to the spindle is regulated by dephosphorylation of a non-catalytic member of the Aurora kinase complex, Sli15p, by Cdc14p (35).

The primary regulator of Aurora Kinase activity, type 1 protein phosphastase Glc7p, acts in opposition to Aurora kinase by dephosphorylating Ipl1p targets, rather than by directly regulating Ipl1p (36, 37, 4, 38, 39, reviewed in 19). Demonstrated Ipl1p phosphorylation targets include: kinetochore components Cbf2p, Mif2p and Tid3p (3, 40, 41); proteins required for spindle assembly or integrity such as Ase1p, Mad3p and Dam1p (42, 43, 44, 9, 45, 46, 29, 47, 48); condensin (49); Histone H3 (50, 51); and Aurora Kinase complex component, Sli15p (9).

There are three Aurora kinase family members in Homo sapiens: (Aurora A, Aurora B, and Aurora C), which vary in function and tissue specificity. Aurora kinases have been implicated in tumorigenesis, and Aurora kinase expression levels and activity have been shown to be up-regulated in many human cancers (52, 53 and reviewed in 54, 55).

Last updated: 2011-04-19 Contact SGD

References cited on this page View Complete Literature Guide for NBL1
1) Nakajima Y, et al.  (2009) Nbl1p: a Borealin/Dasra/CSC-1-like protein essential for Aurora/Ipl1 complex function and integrity in Saccharomyces cerevisiae. Mol Biol Cell 20(6):1772-84
2) Ruchaud S, et al.  (2007) Chromosomal passengers: conducting cell division. Nat Rev Mol Cell Biol 8(10):798-812
3) Biggins S, et al.  (1999) The conserved protein kinase Ipl1 regulates microtubule binding to kinetochores in budding yeast. Genes Dev 13(5):532-44
4) Zhang K, et al.  (2005) The Set1 methyltransferase opposes Ipl1 aurora kinase functions in chromosome segregation. Cell 122(5):723-34
5) Thomas S and Kaplan KB  (2007) A Bir1p Sli15p Kinetochore Passenger Complex Regulates Septin Organization during Anaphase. Mol Biol Cell 18(10):3820-34
6) Shimogawa MM, et al.  (2009) Bir1 is required for the tension checkpoint. Mol Biol Cell 20(3):915-23
7) Makrantoni V and Stark MJ  (2009) Efficient chromosome biorientation and the tension checkpoint in Saccharomyces cerevisiae both require Bir1. Mol Cell Biol 29(16):4552-62
8) Kim JH, et al.  (1999) Sli15 associates with the ipl1 protein kinase to promote proper chromosome segregation in Saccharomyces cerevisiae. J Cell Biol 145(7):1381-94
9) Kang Js JS, et al.  (2001) Functional cooperation of Dam1, Ipl1, and the inner centromere protein (INCENP)-related protein Sli15 during chromosome segregation. J Cell Biol 155(5):763-74
10) Jwa M, et al.  (2008) Regulation of Sli15/INCENP, kinetochore, and Cdc14 phosphatase functions by the ribosome biogenesis protein Utp7. J Cell Biol 182(6):1099-111
11) Li F, et al.  (2000) Cell division regulation by BIR1, a member of the inhibitor of apoptosis family in yeast. J Biol Chem 275(10):6707-11
12) Yoon HJ and Carbon J  (1999) Participation of Bir1p, a member of the inhibitor of apoptosis family, in yeast chromosome segregation events. Proc Natl Acad Sci U S A 96(23):13208-13
13) Gillis AN, et al.  (2005) A novel role for the CBF3 kinetochore-scaffold complex in regulating septin dynamics and cytokinesis. J Cell Biol 171(5):773-84
14) Bouck DC and Bloom KS  (2005) The kinetochore protein Ndc10p is required for spindle stability and cytokinesis in yeast. Proc Natl Acad Sci U S A 102(15):5408-13
15) Widlund PO, et al.  (2006) Phosphorylation of the chromosomal passenger protein Bir1 is required for localization of Ndc10 to the spindle during anaphase and full spindle elongation. Mol Biol Cell 17(3):1065-74
16) Uren AG, et al.  (1999) Role for yeast inhibitor of apoptosis (IAP)-like proteins in cell division. Proc Natl Acad Sci U S A 96(18):10170-5
17) Walter D, et al.  (2006) The inhibitor-of-apoptosis protein Bir1p protects against apoptosis in S. cerevisiae and is a substrate for the yeast homologue of Omi/HtrA2. J Cell Sci 119(Pt 9):1843-51
18) Owsianowski E, et al.  (2008) Negative regulation of apoptosis in yeast. Biochim Biophys Acta 1783(7):1303-10
19) Bouck DC, et al.  (2008) Design features of a mitotic spindle: balancing tension and compression at a single microtubule kinetochore interface in budding yeast. Annu Rev Genet 42:335-59
20) De Wulf P, et al.  (2009) Protein phosphatases take the mitotic stage. Curr Opin Cell Biol 21(6):806-15
21) Zich J and Hardwick KG  (2010) Getting down to the phosphorylated 'nuts and bolts' of spindle checkpoint signalling. Trends Biochem Sci 35(1):18-27
22) Buvelot S, et al.  (2003) The budding yeast Ipl1/Aurora protein kinase regulates mitotic spindle disassembly. J Cell Biol 160(3):329-39
23) Tanaka TU, et al.  (2002) Evidence that the Ipl1-Sli15 (Aurora kinase-INCENP) complex promotes chromosome bi-orientation by altering kinetochore-spindle pole connections. Cell 108(3):317-29
24) Dewar H, et al.  (2004) Tension between two kinetochores suffices for their bi-orientation on the mitotic spindle. Nature 428(6978):93-7
25) Keating P, et al.  (2009) Ipl1-dependent phosphorylation of Dam1 is reduced by tension applied on kinetochores. J Cell Sci 122(Pt 23):4375-4382
26) Tanaka TU  (2005) Chromosome bi-orientation on the mitotic spindle. Philos Trans R Soc Lond B Biol Sci 360(1455):581-9
27) Biggins S and Murray AW  (2001) The budding yeast protein kinase Ipl1/Aurora allows the absence of tension to activate the spindle checkpoint. Genes Dev 15(23):3118-29
28) Pinsky BA, et al.  (2003) An Mtw1 complex promotes kinetochore biorientation that is monitored by the Ipl1/Aurora protein kinase. Dev Cell 5(5):735-45
29) Pinsky BA, et al.  (2006) The Ipl1-Aurora protein kinase activates the spindle checkpoint by creating unattached kinetochores. Nat Cell Biol 8(1):78-83
30) Norden C, et al.  (2006) The NoCut pathway links completion of cytokinesis to spindle midzone function to prevent chromosome breakage. Cell 125(1):85-98
31) Mendoza M, et al.  (2009) A mechanism for chromosome segregation sensing by the NoCut checkpoint. Nat Cell Biol 11(4):477-83
32) Biggins S, et al.  (2001) Genes involved in sister chromatid separation and segregation in the budding yeast Saccharomyces cerevisiae. Genetics 159(2):453-70
33) Woodruff JB, et al.  (2010) Mitotic spindle disassembly occurs via distinct subprocesses driven by the anaphase-promoting complex, Aurora B kinase, and kinesin-8. J Cell Biol 191(4):795-808
34) Vizeacoumar FJ, et al.  (2010) Integrating high-throughput genetic interaction mapping and high-content screening to explore yeast spindle morphogenesis. J Cell Biol 188(1):69-81
35) Pereira G and Schiebel E  (2003) Separase regulates INCENP-Aurora B anaphase spindle function through Cdc14. Science 302(5653):2120-4
36) Francisco L and Chan CS  (1994) Regulation of yeast chromosome segregation by Ipl1 protein kinase and type 1 protein phosphatase. Cell Mol Biol Res 40(3):207-13
37) Francisco L, et al.  (1994) Type 1 protein phosphatase acts in opposition to IpL1 protein kinase in regulating yeast chromosome segregation. Mol Cell Biol 14(7):4731-40
38) Pinsky BA, et al.  (2006) Glc7/protein phosphatase 1 regulatory subunits can oppose the Ipl1/aurora protein kinase by redistributing Glc7. Mol Cell Biol 26(7):2648-60
39) Emanuele MJ, et al.  (2008) Aurora B kinase and protein phosphatase 1 have opposing roles in modulating kinetochore assembly. J Cell Biol 181(2):241-54
40) Westermann S, et al.  (2003) Architecture of the budding yeast kinetochore reveals a conserved molecular core. J Cell Biol 163(2):215-22
41) Akiyoshi B, et al.  (2009) Analysis of Ipl1-mediated phosphorylation of the Ndc80 kinetochore protein in Saccharomyces cerevisiae. Genetics 183(4):1591-5
42) Kotwaliwale CV, et al.  (2007) A Pathway Containing the Ipl1/Aurora Protein Kinase and the Spindle Midzone Protein Ase1 Regulates Yeast Spindle Assembly. Dev Cell 13(3):433-445
43) Rancati G, et al.  (2005) Mad3/BubR1 phosphorylation during spindle checkpoint activation depends on both Polo and Aurora kinases in budding yeast. Cell Cycle 4(7):972-80
44) King EM, et al.  (2007) Ipl1p-dependent phosphorylation of Mad3p is required for the spindle checkpoint response to lack of tension at kinetochores. Genes Dev 21(10):1163-8
45) Li Y, et al.  (2002) The mitotic spindle is required for loading of the DASH complex onto the kinetochore. Genes Dev 16(2):183-97
46) Cheeseman IM, et al.  (2002) Phospho-regulation of kinetochore-microtubule attachments by the Aurora kinase Ipl1p. Cell 111(2):163-72
47) Lampert F, et al.  (2010) The Dam1 complex confers microtubule plus end-tracking activity to the Ndc80 kinetochore complex. J Cell Biol 189(4):641-9
48) Tien JF, et al.  (2010) Cooperation of the Dam1 and Ndc80 kinetochore complexes enhances microtubule coupling and is regulated by aurora B. J Cell Biol 189(4):713-23
49) Lavoie BD, et al.  (2004) In vivo requirements for rDNA chromosome condensation reveal two cell-cycle-regulated pathways for mitotic chromosome folding. Genes Dev 18(1):76-87
50) Hsu JY, et al.  (2000) Mitotic phosphorylation of histone H3 is governed by Ipl1/aurora kinase and Glc7/PP1 phosphatase in budding yeast and nematodes. Cell 102(3):279-91
51) Ramaswamy V, et al.  (2003) Global control of histone modification by the anaphase-promoting complex. Mol Cell Biol 23(24):9136-49
52) Bischoff JR, et al.  (1998) A homologue of Drosophila aurora kinase is oncogenic and amplified in human colorectal cancers. EMBO J 17(11):3052-65
53) Tatsuka M, et al.  (1998) Multinuclearity and increased ploidy caused by overexpression of the aurora- and Ipl1-like midbody-associated protein mitotic kinase in human cancer cells. Cancer Res 58(21):4811-6
54) Fu J, et al.  (2007) Roles of Aurora kinases in mitosis and tumorigenesis. Mol Cancer Res 5(1):1-10
55) Li JJ and Li SA  (2006) Mitotic kinases: the key to duplication, segregation, and cytokinesis errors, chromosomal instability, and oncogenesis. Pharmacol Ther 111(3):974-84