Technical Data
Isoprenylcysteine Carboxymethyl Transferase (ICMT, HSTE14, MGC39955, MST098, MSTP098, PCCMT, PCMT, PPMT)
Isoprenylcysteine carboxyl methyltransferase (ICMT) methylates the carboxyl-terminal isoprenylcysteine of CAAX proteins (e.g., Ras and Rho proteins). In the case of the Ras proteins, carboxyl methylation is important for targeting of the proteins to the plasma membrane. It has been hypothesized that a knockout of ICMT would reduce the ability of cells to be transformed by K-Ras. Fibroblasts harboring a floxed ICMT allele and expressing activated K-Ras (K-Ras-Icmtflx/flx) were treated with Cre-adenovirus, producing K-Ras-Icmt/ fibroblasts. Inactivation of ICMT inhibited cell growth and K-Ras–induced oncogenic transformation, both in soft agar assays and in a nude mice model. The inactivation of ICMT did not affect growth factor–stimulated phosphorylation of Erk1/2 or Akt1. However, levels of RhoA were greatly reduced as a consequence of accelerated protein turnover. In addition, there was a large Ras/Erk1/2-dependent increase in p21Cip1, which was probably a consequence of the reduced levels of RhoA. Deletion of p21Cip1 restored the ability of K-Ras-ICMT/ fibroblasts to grow in soft agar. The effect of inactivating ICMT was not limited to the inhibition of K-Ras–induced transformation: inactivation of ICMT blocked transformation by an oncogenic form of B-Raf (V599E). These studies identify ICMT as a potential target for reducing the growth of K-Ras– and B-Raf–induced malignancies.

Suitable for use in ELISA and Western Blot. Other applications not tested.

Recommended Dilution:
Western Blot: 1:500-1:2000. Lysate from Jurkat cells was resolved by electrophoresis, transferred to PVDF, and probed with I9039-98 for 2 hours at RT. Proteins were visualized via HRP and chemiluminescent detection.
Optimal dilutions to be determined by the researcher.

Storage and Stability:
May be stored at 4°C for short-term only. For long-term storage and to avoid repeated freezing and thawing, add sterile 40-50% glycerol, aliquot and store at -20°C. Aliquots are stable for at least 12 months at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.
PabIgGAffinity Purified
200ul4°C (-20°C Glycerol)Blue IceHumanRabbit
Not Determined
Synthetic peptide corresponding to amino acids 266-281 of human Isoprenylcysteine Carboxymethyl Transferase (KLH).
Purified by immunoaffinity chromatography.
Supplied as a liquid in PBS, 0.09% sodium azide.
Recognizes endogenous human Isoprenylcysteine Carboxymethyl Transferase in Jurkat cell lysate. MW: 34kD.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
1. Bergo, Martin O, et al (2004). Inactivation of Icmt inhibits transformation by oncogenic K-Ras and B-Raf. J Clin Invest 113: 539-50.2. Kramer, Kristina, et al (2003). Isoprenylcysteine carboxyl methyltransferase activity modulates endothelial cell apoptosis. Mol Biol Cell 14: 848-57.