Cell Signaling Technology

Product Pathways - Autophagy Signaling

SignalSilence® ULK1 siRNA I #7000

Applications Reactivity
Transfection H (Mk)

Reactivity Key:  H=Human  Mk=Monkey
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Western Blotting

Western Blotting

Western blot analysis of extracts from RD cells, transfected with 100 nM SignalSilence® Control siRNA (Unconjugated) #6568 (-) or SignalSilence® ULK1 siRNA I (+), using ULK1 (D9D7) Rabbit mAb #6439 (upper) or β-Actin (D6A8) Rabbit mAb #8457 (lower). The ULK1 (D9D7) Rabbit mAb confirms silencing of ULK1 expression, while the β-Actin (D6A8) Rabbit mAb is used as a loading control.

Western Blotting

Western Blotting

Western blot analysis of extracts from RD cells, transfected with 100 nM SignalSilence® Control siRNA (Unconjugated) #6568 (-) or SignalSilence® ULK1 siRNA I (+), using ULK1 (D8H5) Rabbit mAb #8054 (upper) or β-Actin (D6A8) Rabbit mAb #8457 (lower). The ULK1 (D8H5) Rabbit mAb confirms silencing of ULK1 expression, while the β-Actin (D6A8) Rabbit mAb is used as a loading control.

Description

SignalSilence® ULK1 siRNA I from Cell Signaling Technology (CST) allows the researcher to specifically inhibit ULK1 expression using RNA interference, a method whereby gene expression can be selectively silenced through the delivery of double stranded RNA molecules into the cell. All SignalSilence® siRNA products from CST are rigorously tested in-house and have been shown to reduce target protein expression by western analysis.

Quality Control

Oligonucleotide synthesis is monitored base by base through trityl analysis to ensure appropriate coupling efficiency. The oligo is subsequently purified by affinity-solid phase extraction. The annealed RNA duplex is further analyzed by mass spectrometry to verify the exact composition of the duplex. Each lot is compared to the previous lot by mass spectrometry to ensure maximum lot-to-lot consistency.

Directions for Use

CST recommends transfection with 100 nM SignalSilence® ULK1 siRNA I 48 to 72 hours prior to cell lysis. For transfection procedure, follow protocol provided by the transfection reagent manufacturer. Please feel free to contact CST with any questions on use.

Each vial contains the equivalent of 100 transfections, which corresponds to a final siRNA concentration of 100 nM per transfection in a 24-well plate with a total volume of 300 μl per well.

Background

Two related serine/threonine kinases, UNC-51-like kinase 1 and 2 (ULK1, ULK2), were discovered as mammalian homologs of the C. elegans gene UNC-51 in which mutants exhibited abnormal axonal extension and growth (1-4). Both proteins are widely expressed and contain an amino-terminal kinase domain followed by a central proline/serine rich domain and a highly conserved carboxy-terminal domain. The roles of ULK1 and ULK2 in axon growth have been linked to studies showing that the kinases are localized to neuronal growth cones and are involved in endocytosis of critical growth factors, such as NGF (5). Yeast two-hybrid studies found ULK1/2 associated with modulators of the endocytic pathway, SynGAP and syntenin (6). Structural similarity of ULK1/2 has also been recognized with the yeast autophagy protein Atg1/Apg1 (7). Knockdown experiments using siRNA demonstrated that ULK1 is essential for autophagy (8), a catabolic process for the degradation of bulk cytoplasmic contents (9,10). It appears that Atg1/ULK1 can act as a convergence point for multiple signals that control autophagy (11), and can bind to several autophagy-related (Atg) proteins, regulating phosphorylation states and protein trafficking (12-16).

AMPK, activated during low nutrient conditions, directly phosphorylates ULK1 at multiple sites including Ser317, Ser555, and Ser777 (17,18). Conversely, mTOR, which is a regulator of cell growth and an inhibitor of autophagy, phosphorylates ULK1 at Ser757 and disrupts the interaction between ULK1 and AMPK (17).

  1. Ogura, K. et al. (1994) Genes Dev 8, 2389-400.
  2. Kuroyanagi, H. et al. (1998) Genomics 51, 76-85.
  3. Yan, J. et al. (1998) Biochem Biophys Res Commun 246, 222-7.
  4. Yan, J. et al. (1999) Oncogene 18, 5850-9.
  5. Zhou, X. et al. (2007) Proc Natl Acad Sci USA 104, 5842-7.
  6. Tomoda, T. et al. (2004) Genes Dev 18, 541-58.
  7. Matsuura, A. et al. (1997) Gene 192, 245-50.
  8. Chan, E.Y. et al. (2007) J Biol Chem 282, 25464-74.
  9. Reggiori, F. and Klionsky, D.J. (2002) Eukaryot Cell 1, 11-21.
  10. Codogno, P. and Meijer, A.J. (2005) Cell Death Differ 12 Suppl 2, 1509-18.
  11. Stephan, J.S. and Herman, P.K. (2006) Autophagy 2, 146-8.
  12. Okazaki, N. et al. (2000) Brain Res Mol Brain Res 85, 1-12.
  13. Young, A.R. et al. (2006) J Cell Sci 119, 3888-900.
  14. Kamada, Y. et al. (2000) J Cell Biol 150, 1507-13.
  15. Lee, S.B. et al. (2007) EMBO Rep 8, 360-5.
  16. Hara, T. et al. (2008) J Cell Biol 181, 497-510.
  17. Kim, J. et al. (2011) Nat Cell Biol 13, 132-41.
  18. Egan, D.F. et al. (2011) Science 331, 456-61.

Application References

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Companion Products

Limited Use Label License, RNA interference: This product is licensed under European Patent 1144623 and foreign equivalents from Ribopharma AG, Kulmbach, Germany and is provided only for use in non-commercial research specifically excluding use (a) in drug discovery or drug development, including target identification or target validation, by or on behalf of a commercial entity, (b) for contract research or commercial screening services, (c) for the production or manufacture of siRNA-related products for sale, or (d) for the generation of commercial databases for sale to Third Parties. Information about licenses for these and other commercial uses is available from Ribopharma AG, Fritz-Hornschuch-Str. 9, D-95326 Kulmbach, Germany.

For Research Use Only. Not For Use In Diagnostic Procedures.

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