Phospho-ALK (Tyr1278) Antibody (Rabbit mAb) [N16F10] Datasheet

Biological Description

Specificity	Phospho-ALK (Tyr1278) Antibody (Rabbit mAb) [N16F10] detects endogenous levels of total ALK protein only when it is phosphorylated at Tyr1278.
Background	Phospho ALK (Tyr1278) designates the activated form of the receptor tyrosine kinase ALK within its activation loop, a state that underlies oncogenic signaling from full length ALK and ALK fusion proteins in diverse tumors. ALK belongs to the insulin receptor superfamily and contains an extracellular ligand binding region, a single transmembrane helix, and an intracellular kinase domain whose activation loop harbors Tyr1278 together with neighboring tyrosines that undergo autophosphorylation when ligand binding or oncogenic dimerization brings ALK molecules into proximity, converting the kinase from a low activity to a high activity state and enabling efficient phosphorylation of substrates. Substitution of Tyr1278 by polar or charged residues generates ALK variants with constitutive kinase activation, increased autophosphorylation, and ligand independent transforming activity, indicating that phosphorylation or mutation at this position stabilizes the active conformation of the activation loop and removes an autoinhibitory constraint on the catalytic cleft. Activated, Tyr1278 phosphorylated ALK triggers multiple downstream cascades, including PI3K–AKT, RAS–ERK, JAK–STAT, and PLCγ pathways, through phosphorylation of adaptor and docking proteins such as IRS 1, Shc, PLCγ, and other substrates identified by phosphoproteomic profiling, and these pathways together drive proliferation, survival, migration, and transformation in ALK positive tumor cells. Oncogenic ALK activation arises through chromosomal translocations that fuse the ALK kinase domain to oligomerization competent partners such as NPM1 in anaplastic large cell lymphoma and EML4 in non small cell lung cancer, through activating point mutations and amplification in neuroblastoma, and through aberrant overexpression in several additional malignancies; in each setting, constitutive phosphorylation of the activation loop, including Tyr1278, is a biochemical hallmark of the oncogenic kinase state. Phospho specific antibodies that recognize ALK only when phosphorylated at Tyr1278, a site equivalent to Tyr338 in NPM ALK, detect this modification in ALK driven carcinoma cell lines and primary tumors and provide a direct readout of ALK catalytic engagement, complementing genetic assays that identify ALK rearrangements or mutations.

Specificity

Phospho-ALK (Tyr1278) Antibody (Rabbit mAb) [N16F10] detects endogenous levels of total ALK protein only when it is phosphorylated at Tyr1278.

Background

Phospho ALK (Tyr1278) designates the activated form of the receptor tyrosine kinase ALK within its activation loop, a state that underlies oncogenic signaling from full length ALK and ALK fusion proteins in diverse tumors. ALK belongs to the insulin receptor superfamily and contains an extracellular ligand binding region, a single transmembrane helix, and an intracellular kinase domain whose activation loop harbors Tyr1278 together with neighboring tyrosines that undergo autophosphorylation when ligand binding or oncogenic dimerization brings ALK molecules into proximity, converting the kinase from a low activity to a high activity state and enabling efficient phosphorylation of substrates. Substitution of Tyr1278 by polar or charged residues generates ALK variants with constitutive kinase activation, increased autophosphorylation, and ligand independent transforming activity, indicating that phosphorylation or mutation at this position stabilizes the active conformation of the activation loop and removes an autoinhibitory constraint on the catalytic cleft. Activated, Tyr1278 phosphorylated ALK triggers multiple downstream cascades, including PI3K–AKT, RAS–ERK, JAK–STAT, and PLCγ pathways, through phosphorylation of adaptor and docking proteins such as IRS 1, Shc, PLCγ, and other substrates identified by phosphoproteomic profiling, and these pathways together drive proliferation, survival, migration, and transformation in ALK positive tumor cells. Oncogenic ALK activation arises through chromosomal translocations that fuse the ALK kinase domain to oligomerization competent partners such as NPM1 in anaplastic large cell lymphoma and EML4 in non small cell lung cancer, through activating point mutations and amplification in neuroblastoma, and through aberrant overexpression in several additional malignancies; in each setting, constitutive phosphorylation of the activation loop, including Tyr1278, is a biochemical hallmark of the oncogenic kinase state. Phospho specific antibodies that recognize ALK only when phosphorylated at Tyr1278, a site equivalent to Tyr338 in NPM ALK, detect this modification in ALK driven carcinoma cell lines and primary tumors and provide a direct readout of ALK catalytic engagement, complementing genetic assays that identify ALK rearrangements or mutations.

Usage Information

Application

WB, IP

Dilution

WB	IP
1:1000	1:100

Reactivity

Human

Source

Rabbit Monoclonal Antibody

MW

176 kDa

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

References

https://pubmed.ncbi.nlm.nih.gov/19459784/
https://pubmed.ncbi.nlm.nih.gov/29084134/

Phospho-ALK (Tyr1278) Antibody (Rabbit mAb) [N16F10]

Biological Description

Usage Information

References

Application Data