ULK1 Antibodies

Serine/threonine-protein kinase ULK1 (ULK1)

Serine/threonine-protein kinase involved in autophagy in response to starvation. Acts upstream of phosphatidylinositol 3- kinase PIK3C3 to regulate the formation of autophagophores, the precursors of autophagosomes.

Section of regulatory feedback loops in autophagy: acts both as a downstream effector and negative regulator of mammalian target of rapamycin complex 1 (mTORC1) via interaction with RPTOR. Activated via phosphorylation by AMPK and also acts as a regulator of AMPK by mediating phosphorylation of AMPK subunits PRKAA1, PRKAB2 and PRKAG1, resulting in negatively regulate AMPK activity.

Gene Information

Human
Gene Name:	ULK1
Uniprot:	O75385
Entrez:	8408

Family

Belongs to:
protein kinase superfamily

Alternative Names

ATG1 autophagy related 1 homolog; ATG1; ATG1A; EC 2.7.11; EC 2.7.11.1; FLJ38455; FLJ46475; KIAA0722; serine/threonine-protein kinase ULK1; unc-51 (C. elegans)-like kinase 1; UNC51; Unc51.1; unc-51-like kinase 1 (C. elegans); Unc-51-like kinase 1

Molecular Weight

Mass (kDA):
112.631 kDA

Genomic Context

Human
Location:	12q24.33
Sequence:	12; NC_000012.12 (131894622..131923150)

Tissue Specificity

Ubiquitously expressed. Detected in the following adult tissues: skeletal muscle, heart, pancreas, brain, placenta, liver, kidney, and lung.

Subcellular Localizations

Cytoplasm, cytosol. Preautophagosomal structure. Under starvation conditions, is localized to puncate structures primarily representing the isolation membrane that sequesters a portion of the cytoplasm resulting in the formation of an autophagosome.

Diseases

• Malignant Neoplasms
• Neoplasms
• Tissue Adhesions
• Carcinoma
• Physiological Stress
• Nerve Degeneration
• Diabetes Mellitus
• Diabetes Mellitus, Non-insulin-dependent
• Crohn Disease
• Hypoxia
• Lymphoma
• Malignant Paraganglionic Neoplasm

• Cardiotoxicity
• Infective Disorder
• Malignant Neoplasm Of Breast
• Myopathy
• Inflammation
• Neurodegenerative Disorders
• Degenerative Polyarthritis

Interacting Proteins

• AMBRA1
• ATG13
• GABARAPL1
• GABARAPL2
• HTT

• MAP1LC3B
• MAP1LC3C
• MTOR
• NTRK1
• PDPK1

• PRKAA2
• PRKAB1
• RB1CC1
• RPTOR
• TBC1D14

• TRAF6

Pathways

• Autophagy
• Cell Death
• Macroautophagy
• Localization
• Regulation Of Autophagy
• Response To Nutrient
• Transport
• Cellular Homeostasis
• Catabolic Process
• Cell Growth
• Cell Proliferation
• Energy Homeostasis
• Conjugation

• Pathogenesis
• Glycolysis
• Translation
• Vesicle Transport
• Secretion
• Axon Extension
• Interphase

PTMs

• Phosphorylation
• Dephosphorylation

• Acetylation
• Cleavage

• Methylation

Research Areas

• Autophagy
• mTOR Pathway
• Protein Kinase

For details, visit:
bosterbio.com/bosterbio-gene-info-cards/ULK1

Best Uses Of The ULK1 Marker For Raptor

You've arrived at the right spot if you want to learn more about the role ULK1 is involved in the mTOR signaling. In this article, you'll discover how ULK1 regulates the mTOR signaling process and is a phosphorylator of Raptor. You'll also discover the roles of ULK1 in ER export and VSVG transport.

ULK1 kinase regulates mTOR signaling

The molecular mechanism of mTOR signaling have revealed that ULK1 is phosphorylated by a variety of transcriptional factors. The phosphorylation of ULK1 by these transcriptional factors controls the activity of mTOR. The autophagic responses of cells are restricted by ULK1's phosphorylation. The function of ULK1 regulates the expression of downstream targets, including PI3P.

The mTOR pathway plays an significant role in the promotion of anabolic metabolism of cells. This pathway supplies the essential elements required for cell growth and also integrates signaling networks to enhance the production of proteins nucleotides, lipids and lipids. Several upstream regulators can suppress mTORC1, including the tumor suppressor compound (TSC). Its target genes include 4E-BP1, HAMARTIN, and S6K.

ULK1 isn't the only kinase implicated in cancer. SMCR8 is another kinase. The mechanism behind this negative feedback loop is under investigation, but it may be related to AMPK the phosphorylation process. Further research is needed to determine the function of NEDD4L. It is however known that NEDD4L can trigger ULK1 degradation via the proteasome pathway through promoting K27 and K29 polyubiquitination.

In addition the activation of the STING pathway is connected to an increase in the production of cytokines in the liver. The constant progression of liver disease is also linked with an imbalance in the balance between regulatory T cells (Treg) and T helper cells 17 (Th27). It is believed that ULK1 regulates the balance between Th27 and Treg cells. They also propose that ULK1 could regulate balance between Th27 and Treg.

The phosphorylation process of ULK1 is also a key factor in autophagy. The ULK1 complex attaches to the precursor protein ATG9 and thus promotes its translocation. The autophagosome develops and fuses with the Lysosome and forms an autolysosome. This degrades the cargo. These processes require the activation of mTOR signaling molecules and ULK1 Kinase.

The function of ULK1 is not fully understood however, it is believed to be essential for autophagy. Inhibition of ULK1 reduces autophagy, and is crucial for the initiation of autophagy. The deregulation of ULK1 inhibits autophagy in HEK293 cells. Furthermore, fibroblasts from mice deficient in ULK1/2 are not able to stimulate autophagy.

Raptor Phosphorylation

The ULK1 marker for Raptor phosphorylates Raptor at multiple sites within 293 cells. Raptor has three domains that are conserved at the N-terminus, and seven WD40 recursions at the C.terminus. In this test, HA-Raptor or V5-ULK1 was transfected into HEK293 cells. Antibodies to the phosphorylation locations in the Raptor protein were used to determine the presence of ULK1.

Raptor was co-transfected with the ULK1 antibody. Cell lysates were evaluated for phosphorylation Raptor by autoradiography. The HA-Raptor immunoprecipitates then were stained with an anti-HA antibody specific to the cell. The protein concentrations were determined using the same method. This allows researchers to compare phosphorylation states of proteins and cells.

The ULK1 protein binds with the raptor genes. This interaction blocks the mTOR signaling process by phosphorylating Raptor. This could be beneficial for the treatment of various diseases. It is unclear whether increasing ULK expression causes an increase in the mTORC1 signaling pathway. Further studies are required to determine the precise mechanisms through which Raptor interacts with ULK1.

The phosphorylation process of Raptor occurs in response to different signaling inputs. Phosphorylation of Raptor can cause inhibition or activation of mTORC1. Further analysis of ULK1 in Raptor cells is necessary to understand the function it plays in negative regulation of mTORC1.

The ULK1 marker is useful in identifying ULK1-mediated Raptor phosphorylation in cells. In the vivo, ULK1 expression increases mTORC1 activation. This effect can be further enhanced by the expression of Raptor. It also blocks the mTORC1 signaling by activating downstream substrates, such as S6K1 and 4EBP1.

The ULK1 marker might be useful in identifying specific proteins. However it could also be used to predict the activity of other proteins involved in the metabolism of cells. Raptor is a member in the mTOR family. It is also a key regulator of autophagy. The phosphorylation process could play a part in cell proliferation as well as the utilization of energy.

Export regulation of ER

The presence of a distinct SEC16A protein, called TFG, influences the co-localization between ER transport proteins and ULK1. TFG is a protein that promotes the decoating of COPII transporters and maintains them in a zone between ERGIC and ER. Mutations in TFG can cause Charcot's-MarieTooth disease type 2 or sensory axon dysfunction. TFG-related mutations are associated with changes to ER processes.

The ULK1 protein is phosphorylated on Ser-846. This phosphorylation alters the interaction with Sec24C at the ERES. This interaction drives the export of Sec24C-specific cargoes from the ER. Conversely, mutants with no phosphorylation still have the ability to drive ER export. These findings suggest that ULK1 is a key component of the transport process.

In vivo, the depletion of TFG decreases the production of ULK1 and inhibits the autophagy process. These results suggest that TFG could be involved in the regulation of autophagy by altering early autophagy proteins' location. Additionally, disruption of the TFG-LC3C interaction affects ULK1 levels, puncta formation and distribution, and autophagy progression. TFG also favours the interaction of ULK1 with GABARAP. These experiments demonstrate that the ULK1 complex is strongly bound to LC3C, GABARAP, as well as weakly to LC3A, LC3B.

In human cells, ectopic expression WT or ULK1 improves ERES assembly defects in Ulk1/2-deficient MEFs. Transient RNAi-mediated Ulk1 knockdown decreased SEC24C+ pta. This was not affected by deletion or knockdown of the Atg7 gene. The cells lacking ULK1 also showed decreased levels of SEC24C as well as SEC16A.

Autophagy is a major stress response mechanism that involves the mobilization of significant quantities of proteins, lipids and lipids. ER is vital for de novo biogenesis which requires time and space coordination of membrane-bound structures. ER functions as the master regulator of membrane coordination through various MCSs and is crucial for phagophore formation.

The accumulation of TG in the bilayer leads to ER intraluminal budding neutral lipid structures. This procedure requires the presence of the microsomal triglyceride transfer protein. After budding the lipidated Apoliprotein B results in the creation of prelipoproteins inside the cytoplasm. Prechylomicron transporters play a role in this synthesizing.

Regulation of VSVG Transport

Rab6 plays a vital role in the rapid intra-Golgi cargo transport. This transport takes place between the trans-Golgi cisternae as well as the medial cisternae. This happens immediately downstream of the place of normal trans-Golgi localization. It is important to know that Rab6-depleted cells display a delayed cargo transport. Cells depleted of Rab6 show a delayed cargo transport, which could be the reason for the observed delay in the cargo transport.

The intra-Golgi transport rate was greatly affected by the reduction of Rab6. The trans Golgi and medial cisternas was ten times slower after the depletion of Rab6. However, Rab6-depletion had no effect on TGN exit. To investigate the effects of RUSH VSVG and VSVG transport cells that were depleted of Rab6 were utilized. Rab6 knockout cells delayed intra-Golgi transport by release of marker proteins from the ER.

Researchers can permeate GM130 siRNA cells with streptolysin to examine the effects of mitotic CDK1 upon VSV-G transport. The cells are then placed in a mitotic Lysate incubator to determine if permeabilization alters VSV-G transport. The effects of permeation and Golgi fragmentation on the intra-Golgi transport of VSV-G are similar.

In the past, it was shown that the transmembrane movement of VSVG was blocked by siRNA. This effect was extended to the soluble VSVG. The transmembrane domain has been removed from the VSVG-G that has been truncated, which acts as a luminal proteins. Similar inhibition was observed in mast cells of 2H3 rat mitotic. This suggests that VSVG transport is controlled by the movement of soluble protein.