Other Proteins

SIRT2 is a member of the sirtuin family of proteins which are homologs to the yeast Sir2 protein. Sirtuin family contain a sirtuin core domain and are grouped into four classes with SIRT2 being a member of class I. Inhibition of SIRT2 can lead to neuroprotection in cellular and invertebrate models of Huntington's disease (1). Huntington's disease is characterized by increased sterols synthesis in neuronal cells and this process is reversed by SIRT2 inhibition. SIRT2 can deacetylate lys40 of alpha-tubulin both in vitro and in vivo (2). Knockdown of SIRT2 via small interfering RNA results in tubulin hyperacetylation. SIRT2 Protein is ideal for investigators involved in Signaling Proteins, Deacetylase/Demethylase Proteins, Cancer, Cell Cycle, and Inflammation research.

SIRT3 is a member of the sirtuin family of proteins which are homologs to the yeast Sir2 protein. Sirtuin family contain a sirtuin core domain and are grouped into four classes with SIRT3 being a member of class I. SIRT3 contains an N-terminal mitochondrial targeting signal and a central catalytic domain and localizes in the nuclei and mitochondria (1). SIRT3 has NAD(+)-dependent histone deacetylase activity with specificity for lys16 of H4 and, to a lesser extent, lys9 of H3. SIRT3 can repress transcription of a target gene in vivo when recruited to its promoter. Full-length SIRT3 is transported from the nucleus to the mitochondria during cell stress conditions (2). SIRT3 Protein is ideal for investigators involved in Signaling Proteins, Deacetylase/Demethylase Proteins, Cancer, Cell Cycle, and Inflammation research.

SIRT4 is a member of the sirtuin family of proteins which are homologs to the yeast Sir2 protein. Sirtuin family contain a sirtuin core domain and are grouped into four classes with SIRT4 being a member of class IV. SIRT4 lacks deacetylase activity but has ADP-ribosyltransferase activity (1). Immunoprecipitation analysis shows that SIRT4 interacts with the mitochondrial enzyme glutamate dehydrogenase (GDH), and functional analysis show that SIRT4 ADP-ribosylates and inhibits GDH (2). Downregulation of SIRT4 by RNA interference activates GDH, thereby upregulating insulin secretion in response to glucose and amino acids. SIRT4 Protein is ideal for investigators involved in Signaling Proteins, Deacetylase/Demethylase Proteins, Cancer, Cell Cycle, and Inflammation research.

SIRT5 is a member of the sirtuin family of proteins which are homologs to the yeast Sir2 protein. Sirtuin family contain a sirtuin core domain and are grouped into four classes with SIRT5 being a member of class III. SIRT5 consists of eight exons and is found in two isoforms which encode a 310 aa and a 299 aa protein, respectively. Human SIRT5 is most predominantly expressed in heart muscle cells and in lymphoblasts. Fluorescence in situ hybridization analysis localized the human SIRT5 gene to chromosome 6p23. SIRT5 can deacetylate cytochrome c, a protein of the mitochondrial intermembrane space with a central function in oxidative metabolism as well as apoptosis initiation (1). SIRT5 Protein is ideal for investigators involved in Signaling Proteins, Deacetylase/Demethylase Proteins, Cancer, Cell Cycle, and Inflammation research.

SIRT6 is a member of the sirtuin family of proteins which are homologs to the yeast Sir2 protein. Sirtuin family contain a sirtuin core domain and are grouped into four classes with SIRT6 being a member of class IV. Human SIRT6 protein is a NAD(+)-dependent histone H3 lysine-9 deacetylase that modulates telomeric chromatin (1). SIRT6 associates specifically with telomeres and SIRT6 depletion leads to telomere dysfunction with end-to-end chromosomal fusions and premature cellular senescence. SIRT6 -/- mouse cells show that SIRT6 promotes resistance to DNA damage and suppresses genomic instability in association with a role in base excision repair (2). SIRT6 Protein is ideal for investigators involved in Signaling Proteins, Cancer, Cell Cycle, and Inflammation research.

SIRT6 is a member of the sirtuin family of proteins which are homologs to the yeast Sir2 protein. Sirtuin family contain a sirtuin core domain and are grouped into four classes with SIRT6 being a member of class IV. Human SIRT6 protein is a NAD(+)-dependent histone H3 lysine-9 deacetylase that modulates telomeric chromatin (1). SIRT6 associates specifically with telomeres and SIRT6 depletion leads to telomere dysfunction with end-to-end chromosomal fusions and premature cellular senescence. SIRT6 -/- mouse cells show that SIRT6 promotes resistance to DNA damage and suppresses genomic instability in association with a role in base excision repair (2). SIRT6 Protein is ideal for investigators involved in Signaling Proteins, Cancer, Cell Cycle, and Inflammation research.

SMAD1 is a member of the SMAD family which are signal transducers and transcriptional modulators that mediate multiple signaling pathways. The actions of bone morphogenetic proteins (BMPs) are mediated by SMAD1 and SMAD1 can be phosphorylated and activated by the BMP receptor kinase (1). Phosphorylated SMAD1 forms a complex with SMAD4 that is important for its function in the transcription regulation. The SMAD1-SMAD4 complex is a target for SMAD-specific E3 ubiquitin ligases, such as SMURF1 and SMURF2, and undergoes ubiquitination and proteasome-mediated degradation. The formation of a complex between STAT3 and SMAD1, bridged by p300, is involved in the cooperative signaling of LIF and BMP2 and the subsequent induction of astrocytes from neuronal progenitors (2). SMAD1 Protein is ideal for investigators involved in Signaling Proteins, Transcription Proteins, AKT/PKB Pathway, Angiogenesis, Cancer, Cell Cycle, Cellular Stress, ERK/MAPK Pathway, Inflammation, JAK/STAT Pathway, JNK/SAPK P

SMADs are essential intracellular components for the signal transduction of TGFβ family members. SMAD2 is an intracellular mediator of TGFβ family and activin type 1 receptor (1). SMAD2 mediate TGFβ signaling to regulate cell growth and differentiation. SMAD2 is released from cytoplasmic retention by TGFβ receptor-mediated phosphorylation. The phosphorylated SMAD2 then forms a heterodimeric complex with SMAD4, and this complex translocates from cytoplasm into nucleus. By interacting with DNA-binding proteins, SMAD2 complexes then positively or negatively regulate the transcription of target genes. Inactivating mutations in SMAD2 have been found in various cancers (2). SMAD2 Protein is ideal for investigators involved in Signaling Proteins, Transcription Proteins, AKT/PKB Pathway, Angiogenesis, Cancer, Cell Cycle, Cellular Stress, ERK/MAPK Pathway, Inflammation, JAK/STAT Pathway, JNK/SAPK Pathway, NfkB Pathway, and WNT Signaling research.

SMAD3 is a direct mediator of transcriptional activation by the TGFβ receptor. The activity of SMAD3 is regulated by the TGFβ receptors, and SMAD3 is phosphorylated and associated with the ligand-bound receptor complex. TGFβ stimulation leads to phosphorylation and activation of SMAD3, which form a complex with SMAD4 that accumulate in the nucleus and regulate transcription of target genes such as CDK inhibitor (1). SMAD3 containing a C-terminal truncation acts as a dominant-negative inhibitor of the normal TGFβ response. SMAD3 is a major physiologic substrate of the G1 cyclin-dependent kinases CDK4 and CDK2 (2). SMAD3 Protein is ideal for investigators involved in Signaling Proteins, Transcription Proteins, AKT/PKB Pathway, Angiogenesis, Cancer, Cell Cycle, Cellular Stress, ERK/MAPK Pathway, Inflammation, JAK/STAT Pathway, JNK/SAPK Pathway, NfkB Pathway, and WNT Signaling research.