Sir2 belongs to a family of proteins that is found in organisms ranging from bacteria to complex eukaryotes. Members of this family contain a 250 aa core domain that shares about 25-60% sequence identity. Silencing occurs as a series of events initiated by formation of Sir complexes (Sir2, Sir3, Sir4). The complexes are recruited to their chromosome targets via interactions with DNA-binding proteins, followed by deacetylation of histones H3 and H4. A final step required for telomeric silencing is binding of the complex to the deacetylated histones and recruitment of the telosome to the nuclear periphery.6 Sir2 protein is an NAD-dependent histone deacetylase, an enzyme that removes acetyl groups from lysine residues of histone proteins and possibly other substrates. Sir2 transfers acetyl groups from its protein substrates to ADP-ribose and synthesizes o-acetyl-ADP-ribose. Through histone deacetylation, Sir2 may silence chromatin. It appears that Sir2 NAD requirement makes this protein an important player in the pathway that leads to increased life span of several species through calorie restriction. The maintenance or silencing of chromatin may be at the center of processes leading to aging of cells and development of cancer.
Suitable for use in Western Blot, ELISA and Immunohistochemistry. Other applications not tested.
Western Blot: 1-2ug/ml
Immunohistochemistry (Formalin fixed paraffin embedded): 5ug/ml
Optimal dilutions to be determined by the researcher.
Storage and Stability:
May be stored at 4 degrees C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20 degrees C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.