Phospho-Twist (Ser68) Antibody [M15K16] Datasheet

Biological Description

Specificity	Phospho-Twist (Ser68) Antibody [M15K16] detects endogenous levels of total Twist protein only when it is phosphorylated at Ser68.
Background	Phospho‑Twist (Ser68) refers to Twist1 phosphorylated at serine 68, a basic helix–loop–helix transcription factor modification that marks a MAPK‑responsive, stabilized form of the protein linking upstream Ras–RTK–TGF‑β signaling to epithelial–mesenchymal transition, invasion, and drug resistance programs in cancer. Ser68 lies in the N‑terminal regulatory region outside the DNA‑binding basic helix–loop–helix core, and is a major phospho‑acceptor site for ERK1/2, JNK, and p38, which phosphorylate Twist1 at this residue when these kinases are activated by mitogens, oncogenic Ras, or TGF‑β. Phosphorylation at Ser68 reduces Twist1 ubiquitination and proteasomal degradation, increases protein half‑life, and raises steady‑state Twist1 levels without altering TWIST1 transcription, so the Ser68‑phosphorylated pool directly reflects MAPK activity and dictates how much Twist1 is available to form dimers and occupy E‑box–containing promoters and enhancers. Stabilized phospho‑Twist (Ser68) enhances repression of epithelial genes and induction of mesenchymal and invasion‑associated genes, thereby strengthening Twist1‑dependent epithelial–mesenchymal transition, increasing motility and invasiveness of breast cancer cells, and associating with resistance to paclitaxel and other microtubule‑targeting chemotherapy. Levels of Ser68‑phosphorylated Twist1 correlate with total Twist1 and activated JNK in invasive ductal breast carcinomas and are higher in progesterone receptor–negative and HER2‑positive tumors than in other subtypes, highlighting this phospho‑epitope as a readout of aggressive, MAPK‑driven Twist1 signaling in patient samples. Dephosphorylation is mediated by small C‑terminal domain phosphatase 1, which targets Ser(P)68‑Twist1, accelerates Twist1 degradation, and suppresses cell migration and invasion, defining a reversible kinase–phosphatase module that fine‑tunes Twist1 protein turnover and EMT output.

Specificity

Phospho-Twist (Ser68) Antibody [M15K16] detects endogenous levels of total Twist protein only when it is phosphorylated at Ser68.

Background

Phospho‑Twist (Ser68) refers to Twist1 phosphorylated at serine 68, a basic helix–loop–helix transcription factor modification that marks a MAPK‑responsive, stabilized form of the protein linking upstream Ras–RTK–TGF‑β signaling to epithelial–mesenchymal transition, invasion, and drug resistance programs in cancer. Ser68 lies in the N‑terminal regulatory region outside the DNA‑binding basic helix–loop–helix core, and is a major phospho‑acceptor site for ERK1/2, JNK, and p38, which phosphorylate Twist1 at this residue when these kinases are activated by mitogens, oncogenic Ras, or TGF‑β. Phosphorylation at Ser68 reduces Twist1 ubiquitination and proteasomal degradation, increases protein half‑life, and raises steady‑state Twist1 levels without altering TWIST1 transcription, so the Ser68‑phosphorylated pool directly reflects MAPK activity and dictates how much Twist1 is available to form dimers and occupy E‑box–containing promoters and enhancers. Stabilized phospho‑Twist (Ser68) enhances repression of epithelial genes and induction of mesenchymal and invasion‑associated genes, thereby strengthening Twist1‑dependent epithelial–mesenchymal transition, increasing motility and invasiveness of breast cancer cells, and associating with resistance to paclitaxel and other microtubule‑targeting chemotherapy. Levels of Ser68‑phosphorylated Twist1 correlate with total Twist1 and activated JNK in invasive ductal breast carcinomas and are higher in progesterone receptor–negative and HER2‑positive tumors than in other subtypes, highlighting this phospho‑epitope as a readout of aggressive, MAPK‑driven Twist1 signaling in patient samples. Dephosphorylation is mediated by small C‑terminal domain phosphatase 1, which targets Ser(P)68‑Twist1, accelerates Twist1 degradation, and suppresses cell migration and invasion, defining a reversible kinase–phosphatase module that fine‑tunes Twist1 protein turnover and EMT output.

Usage Information

Application

WB, IP

Dilution

WB	IP
1:5000	1:60

Reactivity

Human

Source

Rabbit Monoclonal Antibody

MW

21 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/26975371/
https://pubmed.ncbi.nlm.nih.gov/21502402/

Application Data

WB

Validated by Selleck

Lane 1: HEK-293T, Lane 2: HEK-293T (TWIST1(human)-3×Myc transfected), Lane 3: HEK-293T (TWIST1(human)-3×Myc transfected; alkaline phosphatase, 1h)