What is serine/threonine phosphorylation?

⭐ reaction elements and check point: Ser/Thr phosphorylation occurs on the hydroxyl (-OH) of the serine (Ser) or threonine (Thr) residues on the protein, usually provided by ATP γ-phosphate, catalyzed by Ser/Thr-specific protein kinases (kinases) to form a phosphate ester bond (Ser/Thr-O-PO3 ^ 2-). Dephosphorylation is completed by specific serine/threonine protein phosphatases (phosphatases), restoring the check point to an unmodified state.

⭐ regulatory characteristics: Ser/Thr phosphorylation is highly spatiotemporal specific, and can rapidly and reversibly regulate protein function in different subcellular compartments and signal time courses, so it is one of the important "switches" of cell response to environmental changes, growth and metabolic balance.

⭐ Kinase Spectroscopy and Substrate Recognition: Typical Ser/Thr kinases include PKA, PKC, CAMK, CDKs, AGC/AGC-related family, AMPK, GSK3β, etc.; substrates usually have specific recognition sequences or context structures, and bind kinase catalytic pockets to achieve specific phosphorylation.

Biological functions: from signal transduction to cell fate

Central regulation of signaling pathways

Serine/threonine phosphorylation is a core regulatory mechanism of classical pathways such as MAPK (mitogen-activated protein kinase) and PI3K/AKT/mTOR. For example, the transcription factor c-Jun is activated by phosphorylation at Ser63/73 check point to drive cell proliferation or apoptosis programs; while mTORC1 regulates protein synthesis and metabolic adaptation by phosphorylating downstream targets such as 4E-BP1.

⭐ "Timer" for Cell Cycle and Division

CDK (cyclin-dependent kinase) removes its transcriptional inhibition function by phosphorylating Rb protein (Retinoblastoma protein), promoting cells from G1 phase to S phase; while the activation of APC/C depends on Ser/Thr phosphorylation modification to ensure accurate chromosome separation.

Dynamic balance of ⭐ stress and metabolism

AMPK (AMP-dependent protein kinase) inhibits lipid synthesis through phosphorylation of acetyl-CoA carboxylase (ACC), initiates catabolism when energy is scarce; while under oxidative stress, phosphorylation of Bcl-2 family proteins by JNK (c-Jun N-terminal kinase) can determine the initiation of mitochondrial pathway apoptosis.

Association with disease: from cancer to neurodegenerative diseases

⭐ cancer: Hyperactivation of the PI3K/AKT pathway (e.g. AKT Thr308/Ser473 check point phosphorylation) is strongly associated with tumor resistance; deletion of Ser15 phosphorylation of the tumor suppressor protein p53 can lead to genomic instability.

⭐ Alzheimer's disease: Abnormal hyperphosphorylation of Tau proteins (e.g. Ser202/Thr205 check point) forms nerve fiber tangles

⭐ metabolic syndrome: Ser307 phosphorylation of insulin receptor substrate IRS-1 blocks insulin signaling, promoting insulin resistance and the development of type 2 diabetes.

Related product recommendations

The use of serine/threonine pan-phosphorylated antibodies for WB detection is a very mature and universal detection method. This phosphorylation method provides high-quality antibodies to assist scientific research!

Phospho-Serine/Threonine Recombinant Mouse mAb (S-3496) (Catalog number:  S0B6454 )

WB result of Phospho-Serine/Threonine Recombinant Mouse mAb

Blocking/Diluting buffer and concentration: 5% NFDM/TBST

Primary antibody: Phospho-Serine/Threonine Recombinant Mouse mAb at 1/1000 dilution

Lane 1: untreated HeLa whole cell lysate 20 µg

Lane 2: HeLa starve overnight, then treated with 100 nM Calyculin A for 30 minutes whole cell lysate 20 µg

Secondary antibody: Goat Anti-mouse IgG, (H+L), HRP conjugated at 1/10000 dilution

Predicted MW: Multiple

Observed MW: MultipleStarter phosphorylation-related antibodies: