Product: Phospho-SYK (Tyr323) Antibody
Catalog: AF2008
Description: Rabbit polyclonal antibody to Phospho-SYK (Tyr323)
Application: WB IHC IF/ICC
Reactivity: Human, Mouse, Rat, Monkey
Prediction: Pig, Chicken
Mol.Wt.: 80kDa; 72kD(Calculated).
Uniprot: P43405
RRID: AB_2834436

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 100ul $280 In stock
 200ul $350 In stock

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Product Info

WB 1:500-1:2000, IHC 1:50-1:500, IF/ICC 1:100-1:500
*The optimal dilutions should be determined by the end user.

WB: For western blot detection of denatured protein samples. IHC: For immunohistochemical detection of paraffin sections (IHC-p) or frozen sections (IHC-f) of tissue samples. IF/ICC: For immunofluorescence detection of cell samples. ELISA(peptide): For ELISA detection of antigenic peptide.

Pig(86%), Chicken(100%)
Phospho-SYK (Tyr323) Antibody detects endogenous levels of SYK only when phosphorylated at Tyrosine 323.
Cite Format: Affinity Biosciences Cat# AF2008, RRID:AB_2834436.
The antibody is from purified rabbit serum by affinity purification via sequential chromatography on phospho-peptide and non-phospho-peptide affinity columns.
Rabbit IgG in phosphate buffered saline , pH 7.4, 150mM NaCl, 0.02% sodium azide and 50% glycerol. Store at -20 °C. Stable for 12 months from date of receipt.


EC; kinase Syk; KSYK; KSYK_HUMAN; p72-Syk; p72syk; Spleen tyrosine kinase; Syk; Tyrosine protein kinase SYK; Tyrosine-protein kinase SYK;



Widely expressed in hematopoietic cells (at protein level) (PubMed:8163536). Expressed in neutrophils (at protein level) (PubMed:15123770). Within the B-cell compartment, expressed from pro- and pre-B cells to plasma cells (PubMed:8163536).

Syk is a cytoplasmic tyrosine kinase of the SYK family containing two SH2 domains. Plays a central role in the B cell receptor (BCR) response. An upstream activator of the PI3K, PLCgamma2, and Rac/cdc42 pathways in the BCR response.



Score>80(red) has high confidence and is suggested to be used for WB detection. *The prediction model is mainly based on the alignment of immunogen sequences, the results are for reference only, not as the basis of quality assurance.

Model Confidence:
High(score>80) Medium(80>score>50) Low(score<50) No confidence

PTMs - P43405 As Substrate

Site PTM Type Enzyme
Y28 Phosphorylation
S44 Phosphorylation
Y47 Phosphorylation
K60 Ubiquitination
T73 Phosphorylation
Y74 Phosphorylation
Y91 Phosphorylation
K105 Acetylation
K116 Acetylation
Y131 Phosphorylation P43405 (SYK)
T161 Phosphorylation
S178 Phosphorylation Q13131 (PRKAA1)
S202 Phosphorylation
Y203 Phosphorylation
Y244 Phosphorylation
T256 Phosphorylation
S291 Phosphorylation Q15139 (PRKD1)
S295 Phosphorylation O14757 (CHEK1)
Y296 Phosphorylation
S297 Phosphorylation
S316 Phosphorylation
T317 Phosphorylation
S319 Phosphorylation
Y323 Phosphorylation P07948 (LYN) , P43405 (SYK)
K334 Ubiquitination
T345 Phosphorylation
Y348 Phosphorylation P43405 (SYK) , P07948 (LYN)
S350 Phosphorylation
Y352 Phosphorylation P43405 (SYK) , P07948 (LYN)
Y364 Phosphorylation
S379 Phosphorylation
T384 Phosphorylation
K394 Acetylation
K402 Acetylation
Y431 Phosphorylation
Y484 Phosphorylation
T504 Phosphorylation
Y507 Phosphorylation
K509 Ubiquitination
K517 Ubiquitination
Y525 Phosphorylation P43405 (SYK)
Y526 Phosphorylation P43405 (SYK)
K527 Ubiquitination
T530 Phosphorylation
Y539 Phosphorylation
Y546 Phosphorylation
K571 Acetylation
S579 Phosphorylation
T582 Phosphorylation
K587 Ubiquitination
Y629 Phosphorylation
Y630 Phosphorylation
Y631 Phosphorylation

PTMs - P43405 As Enzyme

Substrate Site Source
O14986 (PIP5K1B) Y105 Uniprot
O43914-2 (TYROBP) Y90 Uniprot
O43914-1 (TYROBP) Y91 Uniprot
O43914-2 (TYROBP) Y101 Uniprot
O43914-1 (TYROBP) Y102 Uniprot
P02730 (SLC4A1) Y8 Uniprot
P02730 (SLC4A1) Y21 Uniprot
P02730 (SLC4A1) Y359 Uniprot
P02730 (SLC4A1) Y904 Uniprot
P05106 (ITGB3) Y785 Uniprot
P05771 (PRKCB) Y662 Uniprot
P06239 (LCK) Y192 Uniprot
P10636 (MAPT) Y18 Uniprot
P11912 (CD79A) S197 Uniprot
P11912 (CD79A) S203 Uniprot
P12318-2 (FCGR2A) Y280 Uniprot
P12318 (FCGR2A) Y281 Uniprot
P12318-2 (FCGR2A) Y287 Uniprot
P12318 (FCGR2A) Y288 Uniprot
P12318-2 (FCGR2A) Y303 Uniprot
P12318 (FCGR2A) Y304 Uniprot
P13569 (CFTR) Y512 Uniprot
P14317-1 (HCLS1) Y378 Uniprot
P14317-1 (HCLS1) Y397 Uniprot
P15498 (VAV1) Y174 Uniprot
P16885 (PLCG2) Y759 Uniprot
P17252 (PRKCA) Y658 Uniprot
P19174 (PLCG1) Y771 Uniprot
P19174 (PLCG1) Y783 Uniprot
P22681 (CBL) Y700 Uniprot
P22681 (CBL) Y731 Uniprot
P22681 (CBL) Y774 Uniprot
P25963 (NFKBIA) Y42 Uniprot
P29353-2 (SHC1) Y239 Uniprot
P29353-2 (SHC1) Y240 Uniprot
P29353-2 (SHC1) Y317 Uniprot
P29353 (SHC1) Y349 Uniprot
P29353 (SHC1) Y350 Uniprot
P29353 (SHC1) Y427 Uniprot
P30307 (CDC25C) S216 Uniprot
P31995 (FCGR2C) Y287 Uniprot
P31995 (FCGR2C) Y310 Uniprot
P37840-2 (SNCA) Y108 Uniprot
P37840 (SNCA) Y125 Uniprot
P37840 (SNCA) Y133 Uniprot
P37840 (SNCA) Y136 Uniprot
P42229 (STAT5A) Y694 Uniprot
P43405-1 (SYK) Y131 Uniprot
P43405-1 (SYK) Y323 Uniprot
P43405-1 (SYK) Y348 Uniprot
P43405 (SYK) Y352 Uniprot
P43405 (SYK) Y525 Uniprot
P43405 (SYK) Y526 Uniprot
P51452 (DUSP3) Y38 Uniprot
P51452 (DUSP3) Y138 Uniprot
P52566 (ARHGDIB) Y24 Uniprot
P68366-1 (TUBA4A) Y432 Uniprot
P78314-1 (SH3BP2) Y174 Uniprot
P78314-1 (SH3BP2) Y183 Uniprot
P78314 (SH3BP2) Y448 Uniprot
Q06187 (BTK) Y551 Uniprot
Q13094 (LCP2) Y113 Uniprot
Q13094 (LCP2) Y128 Uniprot
Q13261 (IL15RA) Y227 Uniprot
Q13422 (IKZF1) S361 Uniprot
Q13422 (IKZF1) S364 Uniprot
Q14289 (PTK2B) Y402 Uniprot
Q8N6F7 (GCSAM) Y107 Uniprot
Q8N6F7 (GCSAM) Y128 Uniprot
Q8WV28 (BLNK) Y72 Uniprot
Q8WV28 (BLNK) Y84 Uniprot
Q8WV28 (BLNK) Y96 Uniprot
Q8WV28 (BLNK) Y178 Uniprot
Q8WV28 (BLNK) Y189 Uniprot
Q92918 (MAP4K1) Y381 Uniprot
Q9GZY6 (LAT2) Y136 Uniprot
Q9GZY6 (LAT2) Y193 Uniprot
Q9GZY6 (LAT2) Y233 Uniprot
Q9ULZ3 (PYCARD) Y146 Uniprot
Q9ULZ3 (PYCARD) Y187 Uniprot

Research Backgrounds


Non-receptor tyrosine kinase which mediates signal transduction downstream of a variety of transmembrane receptors including classical immunoreceptors like the B-cell receptor (BCR). Regulates several biological processes including innate and adaptive immunity, cell adhesion, osteoclast maturation, platelet activation and vascular development. Assembles into signaling complexes with activated receptors at the plasma membrane via interaction between its SH2 domains and the receptor tyrosine-phosphorylated ITAM domains. The association with the receptor can also be indirect and mediated by adapter proteins containing ITAM or partial hemITAM domains. The phosphorylation of the ITAM domains is generally mediated by SRC subfamily kinases upon engagement of the receptor. More rarely signal transduction via SYK could be ITAM-independent. Direct downstream effectors phosphorylated by SYK include VAV1, PLCG1, PI-3-kinase, LCP2 and BLNK. Initially identified as essential in B-cell receptor (BCR) signaling, it is necessary for the maturation of B-cells most probably at the pro-B to pre-B transition. Activated upon BCR engagement, it phosphorylates and activates BLNK an adapter linking the activated BCR to downstream signaling adapters and effectors. It also phosphorylates and activates PLCG1 and the PKC signaling pathway. It also phosphorylates BTK and regulates its activity in B-cell antigen receptor (BCR)-coupled signaling. In addition to its function downstream of BCR plays also a role in T-cell receptor signaling. Plays also a crucial role in the innate immune response to fungal, bacterial and viral pathogens. It is for instance activated by the membrane lectin CLEC7A. Upon stimulation by fungal proteins, CLEC7A together with SYK activates immune cells inducing the production of ROS. Also activates the inflammasome and NF-kappa-B-mediated transcription of chemokines and cytokines in presence of pathogens. Regulates neutrophil degranulation and phagocytosis through activation of the MAPK signaling cascade (By similarity). Required for the stimulation of neutrophil phagocytosis by IL15. Also mediates the activation of dendritic cells by cell necrosis stimuli. Also involved in mast cells activation. Involved in interleukin-3/IL3-mediated signaling pathway in basophils (By similarity). Also functions downstream of receptors mediating cell adhesion. Relays for instance, integrin-mediated neutrophils and macrophages activation and P-selectin receptor/SELPG-mediated recruitment of leukocytes to inflammatory loci. Plays also a role in non-immune processes. It is for instance involved in vascular development where it may regulate blood and lymphatic vascular separation. It is also required for osteoclast development and function. Functions in the activation of platelets by collagen, mediating PLCG2 phosphorylation and activation. May be coupled to the collagen receptor by the ITAM domain-containing FCER1G. Also activated by the membrane lectin CLEC1B that is required for activation of platelets by PDPN/podoplanin. Involved in platelet adhesion being activated by ITGB3 engaged by fibrinogen. Together with CEACAM20, enhances production of the cytokine CXCL8/IL-8 via the NFKB pathway and may thus have a role in the intestinal immune response (By similarity).


Ubiquitinated by CBLB after BCR activation; which promotes proteasomal degradation.

Autophosphorylated. Phosphorylated on tyrosine residues by LYN following receptors engagement. Phosphorylation on Tyr-323 creates a binding site for CBL, an adapter protein that serves as a negative regulator of BCR-stimulated calcium ion signaling. Phosphorylation at Tyr-348 creates a binding site for VAV1. Phosphorylation on Tyr-348 and Tyr-352 enhances the phosphorylation and activation of phospholipase C-gamma and the early phase of calcium ion mobilization via a phosphoinositide 3-kinase-independent pathway (By similarity). Phosphorylated on tyrosine residues in response to IL15. Phosphorylation on Ser-297 is very common, it peaks 5 minutes after BCR stimulation, and creates a binding site for YWHAG. Phosphorylation at Tyr-630 creates a binding site for BLNK. Dephosphorylated by PTPN6.

Subcellular Location:

Cell membrane. Cytoplasm>Cytosol.

Extracellular region or secreted Cytosol Plasma membrane Cytoskeleton Lysosome Endosome Peroxisome ER Golgi apparatus Nucleus Mitochondrion Manual annotation Automatic computational assertionSubcellular location
Tissue Specificity:

Widely expressed in hematopoietic cells (at protein level). Expressed in neutrophils (at protein level). Within the B-cell compartment, expressed from pro- and pre-B cells to plasma cells.

Subunit Structure:

Interacts with LYN; phosphorylates SYK (By similarity). Interacts with RHOH (phosphorylated); regulates mast cells activation (By similarity). Interacts with NFAM1 (phosphorylated); probably involved in BCR signaling (By similarity). Interacts with VAV1 (via SH2 domain); phosphorylates VAV1 upon BCR activation. Interacts with GAB2 (phosphorylated); probably involved in IgE Fc receptor signaling (By similarity). Interacts (via its SH2 domains) with CD79A (via its phosphorylated ITAM domain); the interaction stimulates SYK autophosphorylation and activation (By similarity). Interacts with FCRL3. Interacts (via SH2 domains) with FCER1G (via ITAM domain); activates SYK and mediates neutrophils and macrophages integrin-mediated activation (By similarity). Interaction with FCER1G in basophils triggers IL3-induced IL4 production (By similarity). Interacts with ITGB2 and FGR; involved in ITGB2 downstream signaling (By similarity). Interacts with ITGB3; upon activation by ITGB3 promotes platelet adhesion. Interacts (via SH2 domains) with TYROBP (via ITAM domain); involved in neutrophils and macrophages integrin-mediated activation (By similarity). Interacts with MSN and SELPLG; mediates the selectin-dependent activation of SYK by SELPLG. Interacts with BLNK (via SH2 domain). Interacts (via the second SH2 domain) with USP25 (via C-terminus); phosphorylates USP25 and regulates USP25 intracellular levels. Interacts (via SH2 domains) with CLEC1B (dimer). Interacts with CLEC7A; participates in leukocyte activation in presence of fungal pathogens. Interacts (phosphorylated) with SLA; may regulate SYK through CBL recruitment. Interacts with YWHAG; attenuates BCR-induced membrane translocation and activation of SYK. Interacts (via SH2 domains) with GCSAM; the interaction increases after B-cell receptor stimulation, resulting in enhanced SYK autophosphorylation and activity. Interacts with TNS2; leading to the phosphorylation of SYK. Interacts with FLNA (via filamin repeat 5); docks SYK to the plasma membrane. Interacts with CEACAM1; lipopolysaccharide activated neutrophils induce phosphorylation of SYK resulting in the formation of a complex including TLR4 and the phosphorylated form of SYK and CEACAM1, which in turn, recruits PTPN6 that dephosphorylates SYK, reducing the production of reactive oxygen species (ROS) and lysosome disruption, leading to a reduction of the inflammasome activity (By similarity). Interacts (via SH2 domains) with CEACAM20 (phosphorylated form); the interaction further enhances CEACAM20 phosphorylation (By similarity). Interacts with IL15RA.

(Microbial infection) Interacts with Epstein-Barr virus LMP2A.


The SH2 domains mediate the interaction of SYK with the phosphorylated ITAM domains of transmembrane proteins. Some proteins like CLEC1B have a partial ITAM domain (also called hemITAM) containing a single YxxL motif. The interaction with SYK requires CLEC1B homodimerization.

Belongs to the protein kinase superfamily. Tyr protein kinase family. SYK/ZAP-70 subfamily.

Research Fields

· Environmental Information Processing > Signal transduction > NF-kappa B signaling pathway.   (View pathway)

· Environmental Information Processing > Signal transduction > Phospholipase D signaling pathway.   (View pathway)

· Environmental Information Processing > Signal transduction > PI3K-Akt signaling pathway.   (View pathway)

· Human Diseases > Infectious diseases: Bacterial > Tuberculosis.

· Human Diseases > Infectious diseases: Viral > Epstein-Barr virus infection.

· Human Diseases > Cancers: Overview > Viral carcinogenesis.

· Organismal Systems > Development > Osteoclast differentiation.   (View pathway)

· Organismal Systems > Immune system > Platelet activation.   (View pathway)

· Organismal Systems > Immune system > Natural killer cell mediated cytotoxicity.   (View pathway)

· Organismal Systems > Immune system > B cell receptor signaling pathway.   (View pathway)

· Organismal Systems > Immune system > Fc epsilon RI signaling pathway.   (View pathway)

· Organismal Systems > Immune system > Fc gamma R-mediated phagocytosis.   (View pathway)


1). Inhibition of Spleen Tyrosine Kinase Restores Glucocorticoid Sensitivity to Improve Steroid-Resistant Asthma. Frontiers in Pharmacology, 2022 (PubMed: 35600871) [IF=5.6]

Application: WB    Species: Mouse    Sample: lung tissue

FIGURE 3 The Syk inhibitor R406 enhances Dex-mediated inhibition of MAPK and Syk phosphorylation in an asthmatic mouse model. Twenty-four hours after the last challenge, the phosphorylation of p38 MAPK (A), ERK1/2 (B), JNK (C), GR-Ser226 (D) and Syk (E) was quantified in the right lungs by Western blotting. n = 5/group, *p < 0.05, **p < 0.01, ***p < 0.001, compared with the control group; # p < 0.05, ## p < 0.01, ### p < 0.001, #### p < 0.0001, compared with the asthma model group. △ p < 0.05, compared with the asthma model + Dex treatment group.

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