Visinin-like protein 1 Human E. coli

Introduction to the Molecule

Visinin like protein 1 (VILIP-1, VLP-1 or VSNL-1) is a cytoplasmic protein of low molecular weight (approximately 22 kDa) consisting of 191 amino acid residues. It belongs to the visinin/recoverin subfamily of neuronal calcium sensor proteins involved in calcium-dependent signal transduction mechanisms in neurons. It is found primarily in the brain, in nerve cells, but it also has a peripheral distribution in liver, lung, kidney, spleen, pancreas and colon. When localized at the membrane, it modulates various cellular signal transduction pathways, including cyclic adenosine monophosphate (cAMP)- and cyclic guanosine monophosphate (cGMP)-signaling in neural cells, human embryonic kidney cells, the pancreatic β cell line MIN6, and various skin tumor cell lines. It contains four internal repeats of 36–38 amino-acids, each containing a potential EF-hand domain. Two of the four EF-hand Ca2+-binding motifs of VILIP-1 are able to bind either Ca2+ or Mg2+in a non-cooperative manner. Binding of Ca2+ leads to specific conformational changes in the protein and this may regulate the interaction of VILIP with intracellular target molecules. VILIP-1 has been identified as a potential biomarker for brain injury and several neurodegenerative diseases. VILIP-1-expressing cells appear to be vulnerable to neurotoxic insults. As a result, the protein is released into the cerebrospinal fluid (CSF), and can be used as a biomarker for stroke and Alzheimer’s di­sease. The intracellular protein was detected in cerebrospinal fluid (CSF) of a rat model of stroke and in plasma of patients after stroke. VILIP-1 was detected in 44% of subjects with stroke, in samples taken 24 hours after onset of stroke, and in 8% of controls with no stroke. In Alzheimer’s di­sease, CSF levels of VILIP-1 were significantly higher than in healthy individuals. Post mortem studies in the hippocampus of schizophrenia patients revealed increased expression of VILIP-1 in interneurons, while its expression in pyramidal neurons was downregulated. Expressions of VILIP-1 were also found in different types of cancer and in pancreatic α- and β-cells, being involved in the regulation of insulin secretion and insulin gene expression.

Research topic

Neural tissue damage markers, Oncology

Description

Total 201 AA. MW: 23.4 kDa (calculated). N-terminal His-tag, 10 extra AA (highlighted). The AA sequence is identical to UniProtKB/Swiss-Prot entry P62760.

Amino Acid Sequence

Source

E. coli

SDS-PAGE gel

12% SDS-PAGE separation of Human VILIP 1. M.W. marker – 14, 21, 31, 45, 66, 97 kDa 2. reduced and heated sample, 5μg/lane 3. non-reduced and non-heated sample, 5μg/lane

Endotoxin

< 1.0 EU/ug

Formulation

Filtered (0.4 μm) and lyophilized from 0.5 mg/ml in 20mM Tris buffer, 20mM NaCl, pH 7.5

Reconstitution

Add deionized water to prepare a working stock solution of approximately 0.5 mg/mL and let the lyophilized pellet dissolve completely. Product is not sterile! Please filter the product by an appropriate sterile filter before using it in the cell culture.

Storage, Stability/Shelf Life

Store lyophilized protein at –20°C. Lyophilized protein remains stable until the expiry date when stored at –20°C. Aliquot reconstituted protein to avoid repeated freezing/thawing cycles and store at –80°C for long term storage. Reconstituted protein can be stored at 4°C for a limited period of time; it does not show any change after one week at 4°C.

Quality Control Test

BCA to determine quantity of the protein.

SDS PAGE to determine purity of the protein.

LAL to determine quantity of endotoxin.

Applications

Western blotting

Note

This product is intended for research use only.

References

• Anand R, Braunewell KH, Gundelfinger ED, Treuil M, Jeanclos EM, Lin L. The calcium sensor protein visinin-like protein-1 modulates the surface expression and agonist sensitivity of the alpha 4beta 2 nicotinic acetylcholine receptor. J Biol Chem. 2002 Nov 1;277 (44):41872-8
• Braunewell KH. VILIP-1. UCSD-Nature Molecule Pages. 2009;
• Braunewell KH, Brackmann M, Anand R, Schuchmann S. Neuronal Ca2+ sensor protein VILIP-1 affects cGMP signalling of guanylyl cyclase B by regulating clathrin-dependent receptor recycling in hippocampal neurons. J Cell Sci. 2005 Jun 1;118 (Pt 11):2495-505
• Braunewell KH, Gierke P, Zhao C, Bernstein HG, Noack C, Anand R, Heinemann U. Implication of neuronal Ca2+ -sensor protein VILIP-1 in the glutamate hypothesis of schizophrenia. Neurobiol Dis. 2008 Oct;32 (1):162-75
• Burgoyne RD. The neuronal calcium- sensor proteins. Biochimica et Biophysica Acta. 2004;
• Chen KC, Wang LK, Chang LS. Regulatory elements and functional implication for the formation of dimeric visinin-like protein-1. J Pept Sci. 2009 Feb;15 (2):89-94
• Klein-Szanto AJ, Braunewell KH. Visinin-like proteins (VSNLs): interaction partners and emerging functions in signal transduction of a subfamily of neuronal Ca2+ -sensor proteins. Cell Tissue Res. 2009 Feb;335 (2):301-16
• Klein-Szanto AJ, Ibanez de Caceres I, Cairns P, Zhang J, Jin F, Bassi DE, Apostolou S, Ross E, Bellacosa A, Fong K, Fu J, Braunewell KH. VILIP-1 downregulation in non-small cell lung carcinomas: mechanisms and prediction of survival. PLoS One. 2008;3 (2):e1698
• Ladenson JH, Lee JM, Landt Y, Olander JV, Crimmins DL, Modur VR, Laterza OF. Identification of novel brain biomarkers. Clin Chem. 2006 Sep;52 (9):1713-21
• Ladenson JH, Ohlendorf M, Gao F, Olander J, Modur V, Laterza O, Andreasen N, Blennow K, Lee JM. The brain injury biomarker VLP-1 is increased in the cerebrospinal fluid of Alzheimer disease patients. Clin Chem. 2008 Oct;54 (10):1617-23
• Schnurra I, Bernstein HG, Riederer P, Braunewell KH. The neuronal calcium sensor protein VILIP-1 is associated with amyloid plaques and extracellular tangles in Alzheimer's disease and promotes cell death and tau phosphorylation in vitro: a link between calcium sensors and Alzheimer's disease?. Neurobiol Dis. 2001 Oct;8 (5):900-9
• Verbeek MM, Olde Rikkert MG. Cerebrospinal fluid biomarkers in the evaluation of Alzheimer disease. Clin Chem. 2008 Oct;54 (10):1589-91
• Wheeler MB, Chan CB, Braunewell KH, Gaisano HY, Kang Y, Wang Q, Zhang Y, Dai FF. The neuronal Ca2+ sensor protein visinin-like protein-1 is expressed in pancreatic islets and regulates insulin secretion. J Biol Chem. 2006 Aug 4;281 (31):21942-53

By research topic:

• Neural tissue damage markers
• Oncology

By molecule:

• Visinin-like protein 1