Bub1 Antibody [N20E21] | Primary Antibodies

Application: Reactivity: Mouse, Rat, Human

Usage Information

Dilution
WB1:1000 IHC1:50 IF1:100

Application
WB, IHC, IF

Reactivity
Mouse, Rat, Human

Source
Rabbit Monoclonal Antibody

Storage Buffer
PBS, pH 7.2+50% Glycerol+0.05% BSA+0.01% NaN3

Storage (from the date of receipt)
-20°C (avoid freeze-thaw cycles), 2 years

Predicted MW Observed MW
122 kDa 122 kDa, 125 kDa
^*Why do the predicted and actual molecular weights differ? The following reasons may explain differences between the predicted and actual protein molecular weight.

Positive Control	Rat testis; Human testis; Mouse testis; Human fetal liver; HAP1 cells; HeLa cells; F9 cells; K562 cells; U-2 OS cells
Negative Control

Datasheet & SDS

Biological Description

Specificity
Bub1 Antibody [N20E21] detects endogenous levels of total Bub1 protein.

Clone
N20E21

Synonym(s)
BUB1L; BUB1; Mitotic checkpoint serine/threonine-protein kinase BUB1; hBUB1; BUB1A

Background
Bub1 (Budding Uninhibited by Benzimidazoles 1), a conserved serine/threonine kinase essential for the spindle assembly checkpoint (SAC), localizes to unattached kinetochores where it orchestrates mitotic arrest by phosphorylating targets that inhibit the anaphase-promoting complex/cyclosome (APC/C) until all chromosomes achieve bipolar microtubule attachment. Bub1 features an N-terminal kinetochore-binding domain with a KTBLT motif that recruits Bub3, a central serine/threonine-rich domain for Mad1/Mad2 recruitment, and a C-terminal kinase domain with a conserved DFG motif where autophosphorylation at multiple sites, including the activation loop, coordinates with Plk1 to multiply phosphorylate Cdc20 (S92/S153), creating a phospho-epitope barrier that prevents APC/C-Cdc20 activation. Bub1 kinase activity generates the "wait-anaphase" signal by scaffolding Bub3, Plk1, and Cdc20 at kinetochores, while kinase-independent functions recruit SAC effectors such as Mad1/2 and BubR1 that are essential for checkpoint stringency. Bub1 also directly promotes proper chromosome segregation through centromeric histone H2A phosphorylation at Ser121, stabilizing kinetochore-microtubule attachments independent of SAC signaling. Bub1 ensures genomic stability during cell division, while pathologically, hypomorphic expression causes chromosome missegregation and aneuploidy that drive tumorigenesis in lung and colon cancers, and overexpression predicts chemotherapy or radiation resistance by enhancing SAC-mediated survival.

Background

Bub1 (Budding Uninhibited by Benzimidazoles 1), a conserved serine/threonine kinase essential for the spindle assembly checkpoint (SAC), localizes to unattached kinetochores where it orchestrates mitotic arrest by phosphorylating targets that inhibit the anaphase-promoting complex/cyclosome (APC/C) until all chromosomes achieve bipolar microtubule attachment. Bub1 features an N-terminal kinetochore-binding domain with a KTBLT motif that recruits Bub3, a central serine/threonine-rich domain for Mad1/Mad2 recruitment, and a C-terminal kinase domain with a conserved DFG motif where autophosphorylation at multiple sites, including the activation loop, coordinates with Plk1 to multiply phosphorylate Cdc20 (S92/S153), creating a phospho-epitope barrier that prevents APC/C-Cdc20 activation. Bub1 kinase activity generates the "wait-anaphase" signal by scaffolding Bub3, Plk1, and Cdc20 at kinetochores, while kinase-independent functions recruit SAC effectors such as Mad1/2 and BubR1 that are essential for checkpoint stringency. Bub1 also directly promotes proper chromosome segregation through centromeric histone H2A phosphorylation at Ser121, stabilizing kinetochore-microtubule attachments independent of SAC signaling. Bub1 ensures genomic stability during cell division, while pathologically, hypomorphic expression causes chromosome missegregation and aneuploidy that drive tumorigenesis in lung and colon cancers, and overexpression predicts chemotherapy or radiation resistance by enhancing SAC-mediated survival.

References
https://pubmed.ncbi.nlm.nih.gov/22331848/ https://pubmed.ncbi.nlm.nih.gov/26148513/

Reference Table for Selecting PVDF Membrane Pore Size Specifications

Protein Size (kDa)	PVDF Transfer Membrane Pore Size (μm)
< 10	0.22
10-20	0.22
20-30	0.45
30-45	0.45
45-70	0.45
80-100	0.45
100-140	0.45
> 140	0.45

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Protein Size (kDa)	Separating Gel Percentage
4-40	20%
12-45	15%
10-70	12.5%
15-100	10%
25-100	8%
60-210	5%