Ki67: Ki67 Protein | Ki67 Antibody

Ki67 Gene family

Ki67 Background

MKI67 contains 1 FHA domain and plays a key role in cell proliferation. During interphase, the MKI67 antigen can be exclusively detected within the cell nucleus, whereas in mitosis most of the protein is relocated to the surface of the chromosomes. MKI67 protein is present during all active phases of the cell cycle (G1, S, G2, and mitosis), but is absent from resting cells. MKI67 is an excellent marker to determine the growth fraction of a given cell population. The fraction of MKI67-positive tumor cells is often correlated with the clinical course of cancer. It is also associated with ribosomal RNA transcription. Inactivation of antigen MKI67 leads to inhibition of ribosomal RNA synthesis.The MKI67 protein is a nuclear and nucleolar protein, which is tightly associated with somatic cell proliferation. Antibodies raised against the human MKI67 protein paved the way for the immunohistological assessment of cell proliferation, particularly useful in numerous studies on the prognostic value of cell growth in clinical samples of human neoplasms. MKI67 protein expression is an absolute requirement for progression through the cell-division cycle. Recently, MKI67 is proved be an independent prognostic factor for disease-free survival (HR 1.5-1.72) in multivariate analyses studies using samples from randomized clinical trials with secondary central analysis of the biomarker. MKI67 was not found to be predictive for long-term follow-up after chemotherapy. Nevertheless, high KI-67 was found to be associated with immediate pathological complete response in the neoadjuvant setting, with an LOE of II-B. MKI67 could be considered as a prognostic biomarker for therapeutic decision.<p/>

Reference for Ki67

  • Rahmanzadeh R, et al. (2007) Chromophore-assisted light inactivation of pKi-67 leads to inhibition of ribosomal RNA synthesis. Cell Prolif. 40(3):422-30.
  • Bullwinkel J, et al. (2006) Ki-67 protein is associated with ribosomal RNA transcription in quiescent and proliferating cells. J Cell Physiol. 206(3):624-35.
  • Schonk DM, et al. (1989) Assignment of the gene(s) involved in the expression of the proliferation-related Ki-67 antigen to human chromosome 10. Hum Genet. 83(3):297-9.
  • Endl E, et al., 2000, Exp Cell Res. Jun 15;257(2): 231-7.
  • Luporsi E, et al., 2012, Breast Cancer Res Treat. 132(3): 895-915.
  • Scholzen T, et al., 2000, J Cell Physiol. 182(3): 311-22.

Ki67 Protein

Ki67 protein function

Required to maintain individual mitotic chromosomes dispersed in the cytoplasm following nuclear envelope disassembly (PubMed:27362226). Associates with the surface of the mitotic chromosome, the perichromosomal layer, and covers a substantial fraction of the chromosome surface (PubMed:27362226). Prevents chromosomes from collapsing into a single chromatin mass by forming a steric and electrostatic charge barrier: the protein has a high net electrical charge and acts as a surfactant, dispersing chromosomes and enabling independent chromosome motility (PubMed:27362226). Binds DNA, with a preference for supercoiled DNA and AT-rich DNA (PubMed:10878551). Does not contribute to the internal structure of mitotic chromosomes (By similarity). May play a role in chromatin organization (PubMed:24867636). It is however unclear whether it plays a direct role in chromatin organization or whether it is an indirect consequence of its function in maintaining mitotic chromosomes dispersed (Probable). {ECO:0000250|UniProtKB:E9PVX6, ECO:0000269|PubMed:10878551, ECO:0000269|PubMed:24867636, ECO:0000269|PubMed:27362226}.

Ki67 protein expression

Induction

Expression occurs preferentially during late G1, S, G2 and M phases of the cell cycle, while in cells in G0 phase the antigen cannot be detected (at protein level) (PubMed:6206131). Present at highest level in G2 phase and during mitosis (at protein level). In interphase, forms fiber-like structures in fibrillarin-deficient regions surrounding nucleoli (PubMed:2674163, PubMed:8799815).

Ki67 protein sequence

This sequence information is just for reference only.From Uniport

  • Length
    3,256.00
  • Mass (Da)
    358.00

Ki67 Antibody

There are 9 Ki67 antibodies which are validated in multiple tissues with various applications, including ICC/IF, IHC-P, WB, ELISA. There are 2 Ki67 antibody for ICC/IF, 4 Ki67 antibody for IHC-P, 3 Ki67 antibody for WB, 2 Ki67 antibody for ELISA. Among all these Ki67 antibodies, there are 5 anti-Ki67 mouse monoclonal antibodies , 4 anti-Ki67 rabbit polyclonal antibodies . All the Ki67 anbodies are produced in house and all are in stock. Ki67 antibody customerized service is available.

Ki67 Gene

MKI67 gene / cDNA is a protein-coding gene which located on 10q26.2. The MKI67 gene is conserved in chimpanzee, Rhesus monkey, dog, cow, mouse, and rat.193 organisms have orthologs with human gene MKI67.