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SIRT6 is part of the sirtuin family of proteins (Class IV), homologs to the yeast Sir2 protein. SIRT6 is characterized by a sirtuin core domain. Yeast sirtuin proteins are recognized by their ability to regulate epigenetic gene silencing and suppress recombination of rDNA. SIRT6, a chromatin-associated protein is involved in DNA repair. Human Sirtuins function as intracellular regulatory proteins with mono-ADP-ribosyltransferase activity.

Sirtuin-1 (SIRT1) belongs to the sirtuin family of proteins, homologs to the yeast Sir2 protein. Sirtuin family members are characterized by a sirtuin core domain and grouped into 4 classes. The functions of human sirtuins have not yet been established; though, yeast sirtuin proteins are known to regulate epigenetic gene silencing and suppress recombination of rDNA. It has been proposed that the human sirtuins may serve as intracellular regulatory proteins with mono-ADP-ribosyltransferase activity.

SIRT3 is a member of a family of proteins called Sirtuin. Proteins of the Sirtuin family are characterized by a Sirtuin core domain and grouped into four classes. The roles of human Sirtuins are numerous and are important in aging prosseses, stress resistance and metabolic regulation. SIRT3 shows NAD+-dependent deacetylase activity in the mitochondria. Over-expression of SIRT3 causes increased levels of the mitochondrial uncoupling protein 1. Also, in certain breast cancers the levels of SIRT3 protein are found to be extremely high.

SIRT2 belongs to the sirtuin family of proteins, homologs to the yeast Sir2 protein. Proteins of the sirtuin family are characterized by a sirtuin core domain and grouped into four classes and take part in various processes, including transcriptional regulation, cell cycle progression, DNA-damage repair and aging. SIRT2 is a NAD-dependent deacetylase, which deacetylates the 'Lys-40' of alpha-tubulin.

SIRT5 belongs to the Sirtuin family of proteins, homologs to the yeast Sir2 protein. Sirtuin family members hold a sirtuin core domain and grouped into four classes. The protein encoded by this gene is included in class III of the sirtuin family. Human sirtuins functions were not yet determined; still, yeast sirtuin proteins are known to regulate epigenetic gene silencing and suppress recombination of rDNA. Studies propose that human sirtuin could operate as intracellular regulatory protein with mono-ADP-ribosyltransferase activity.

SERTA domain-containing protein (SERTAD1) functions with E2F-responsive promoters to integrate signals provided by PHD- and/or bromodomain-containing transcription factors. SERTAD1 stimulates E2F-1/DP-1 transcriptional activity. SERTAD1 reduces the activity of cyclin D1/CDK4 resistant to the inhibitory effects of p16(INK4a). In addition, SERTAD1 interacts with the PHD-bromodomain of TIF1, TRIM28/TIF1B and p300/CBP. Furthermore, SERTAD1 binds to DP1 and interacts with CDK4.

Signaling threshold-regulating transmembrane adapter 1 (SIT1) negatively regulates T-cell antigen receptor (TCR)-mediated signaling in T-cells. SIT1 is involved in positive selection of T-cells. SIT1 is specifically expressed in T- and B-cells. SIT1 is also present in plasma cells but not in germinal center B-cells (at protein level). SIT1 is expressed in T- and B-cell lymphoma.

SERTA domain containing 2 (SERTAD2) takes part at E2F-responsive promoters to integrate signals which are given by PHD- and bromodomain-containing transcription factors. The SERTAD2 protein is taking part in modulating fat storage by down-regulating the expression of key genes which take part in thermogenesis, adipocyte lipolysis and oxidative metabolism.

PMSG Hormone is a well know used hormone together with progestogen to increase ovulation just before to artificial insemination. PMSG hormone is a placental glycoprotein produced from the serum of pregnant mares. PMSG comprises of an alfa subunit and a beta subunit. PMSG hormone is secreted from endometrial cups within the pregnant mare uterus aging from 40 to 130 days into their maturation, and once extracted, it can been used to promote artificially estrus in female animals. These assemblies produce PMSG hormone to induce mare's ovarian and repsouctive structures. PMSG can induce the growth of follicles by ovaries and results in ovulatation. PMSG hormone has an about a 4 day half-life of bioactivity in species other than horses. The extended biological activity can cause ovarian stimulation and ovulation. However, PMSG use alone often causes cystic ovarian disease because of the unrestrained ovarian stimulation and due to the sugar molecules which decrease clearance of the hormone. PMSG is more likely to be used than other pituitary hormones due to the extended circulatory half-life. PMSG solely exhibits luteinizing hormone like activity, however in other animal classes it has FSH & LH like activity.

The somatomedins, or insulin-like growth factors (IGFs), comprise a family of peptides that play important roles in mammalian growth and development. IGF1 mediates many of the growth-promoting effects of growth hormone (GH; MIM 139250). Early studies showed that growth hormone did not directly stimulate the incorporation of sulfate into cartilage, but rather acted through a serum factor, termed 'sulfation factor,' which later became known as 'somatomedin' (Daughaday et al., 1972). Three main somatomedins have been characterized: somatomedin C (IGF1), somatomedin A (IGF2; MIM 147470), and somatomedin B (MIM 193190) (Rotwein, 1986; Rosenfeld, 2003).

Signal-Regulatory Protein Gamma (SIRPG) belongs to the signal-regulatory protein (SIRP) family whose members are receptor-type transmembrane glycoproteins which negatively regulate the receptor tyrosine kinase-coupled signaling processes. SIRPG is also a part of the immunoglobulin superfamily.

Stratifin is part of the 14-3-3 family. The 14-3-3 family of proteins plays an important regulatory function in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are 7 isoforms, beta, gamma, epsilon, sigma, zeta, tau and eta that have been identified in mammals. Stratifin is an epithelial cell marker that functions as a tumor suppressor whose expression can be down regulated via methylation. Failure of Stratifin expression results in a defective G2/M phase checkpoint and results in epithelial and non-epithelial tumorigenesis.

Synaptotagmin-4 (SYT4) is a part of the synaptotagmin proteins family. Synaptotagmins are a large gene family of synaptic vesicle type III integral membrane proteins that operate as regulators of both exocytosis and endocytosis and are involved in neurotransmitter secretion from small secretory vesicles. SYT4 is expressed in neuronal tissues, and has the highest mRNA levels in the hippocampus. The proximity of the SYT4 gene to markers of several psychiatric disorders implies an involvement of SYT4 in human disease such as pheochromocytoma, and parkinson's disease.

GADD45GIP1 is a nuclear protein which takes part in apoptosis control. GADD45GIP1 is expressed in several tissues, such as heart, thyroid, trachea, kidney, ovary, pancreas, testis and stomach and acts as a negative regulator of G1 to S phase cell cycle production by collaborating with GADD45 proteins to inhibit the activity of cyclin-dependent kinases.

Synaptotagmin-1(SYT1) is a member of the synaptotagmin family, which contains two C2 domains. The synaptotagmins are integral membrane proteins of synaptic vesicles assumed to function as Ca(2+) sensors in the process of vesicular trafficking and exocytosis. SYT1 is the principal regulator responsible for allowing the human brain to release neurotransmitters. SYT1 may have a regulatory role in the membrane interactions during trafficking of synaptic vesicles at the active zone of the synapse. SYT1 binds acidic phospholipids with a specificity which entails the presence of both an acidic head group and a diacyl backbone. SYT1 can also bind to at least 3 additional proteins in a Ca2+-independent manner; these being neurexins, syntaxin and AP2.

Signal-Regulatory Protein Gamma (SIRPG) belongs to the signal-regulatory protein (SIRP) family whose members are receptor-type transmembrane glycoproteins which negatively regulate the receptor tyrosine kinase-coupled signaling processes. SIRPG is also a part of the immunoglobulin superfamily.

Signal-regulatory protein beta-1 isoform 1 or SIRPB1, is an immunoglobulin-like cell surface receptor which is a part of the SIRP superfamily. SIRPB1 is a cell membrane receptor that takes part in the negative regulation of tyrosine kinase-coupled signaling pathway. SIRPB1 is engaged in the activation of tyrosine kinase SYK, SIRP alpha molecules (activates SHP-1 and SHP-2 protein tyrosine phosphatases), etc.

OTOR proteins is also known as fibrocyte-derived protein (Fdp) and Melanoma inhibitory activity-like (MIAL). Otoraplin is a member of the melanoma-inhibiting activity gene family. Otoraplin is a secreted 16 kDa globular protein that is expressed in the inner ear by periotic mesenchyme and developing and mature fibrocytes. OTOR is highly homologous to MIA/cartilage-derived retinoic acid-sensitive protein (CD-RAP), which is a cartilage-specific protein that is also expressed in malignant melanoma cells. The 111 amino acid mature human otoraplin contains 1 SH3 domain (46 – 107 amino acids) and a Tyr at position 50 that is reportedly sulfated. Otoraplin takes pasrt in the initiation of periotic mesenchyme chondrogenesis.
Otoraplin is secreted through the Golgi apparatus and plays a role in cartilage development and maintenance. A frequent polymorphism in the translation start codon of OTOR can abolish translation and may be associated with forms of deafness.

Seryl-tRNA synthetase, cytoplasmic (SARS) is a member of the class-II aminoacyl-tRNA synthetase family. Aminoacyl-tRNA synthetases’ role is to catalyze the aminoacylation of tRNAs by their corresponding amino acids, as a result linking amino acids with tRNA-contained nucleotide triplets. The SARS enzyme catalyzes the attachment of serine to tRNA (Ser). SARS enzyme is probably able to aminoacylate tRNA (Sec) with serine, to form the misacylated tRNA L-seryl-tRNA (Sec), which will be then converted into selenocysteinyl-tRNA (Sec).

Signal-Regulatory Protein Alpha, SIRPA belongs to the signal-regulatory-protein (SIRP) family, as well as theimmunoglobulin super family. The members of the SIRP family are receptor-type transmembrane glycoproteins which areinvolved in the negative regulation of receptor tyrosine kinase-coupled signaling processes. SIRPA can bephosphorylated by tyrosine kinases. The phospho-tyrosine residues of this PTP have been shown to recruit SH2domain containing tyrosine phosphatases (PTP), and perform as substrates of PTPs. SIRPA take part insignal transduction mediated by a variety of growth factor receptors. CD47 has been shown to be a ligand forSIRPA.

Signal-Regulatory Protein Alpha, SIRPA belongs to the signal-regulatory-protein (SIRP) family, as well as the immunoglobulin super family. The members of the SIRP family are receptor-type transmembrane glycoproteins which are involved in the negative regulation of receptor tyrosine kinase-coupled signaling processes.
SIRPA can be phosphorylated by tyrosine kinases. The phospho-tyrosine residues of this PTP have been shown to recruit SH2 domain containing tyrosine phosphatases (PTP), and perform as substrates of PTPs. SIRPA take part in signal transduction mediated by a variety of growth factor receptors. CD47 has been shown to be a ligand for SIRPA.

Synaptotagmin-11 (SYT11) protein may be involved in Ca2+-dependent exocytosis of secretory vesicles through Ca2+ and phospholipid binding to the C2 domain or may function as Ca2+ sensors in the process of vesicular trafficking and exocytosis.

SPINT2 is a transmembrane protein acts as an inhibitor of HGF activator. SPINT2 inhibits plasmin, plasma and tissue kallikrein, and factor XIa. SPINT2 has two extracellular Kunitz domains that inhibit few serine proteases. SPINT2 is assumed tumor suppressor, mutations in SPINT2 leads to a congenital sodium diarrhea.

Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin. Streptavidin is widely used in molecular biology through its unique high affinity for the vitamin biotin. The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L. The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits. The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14). The complexes are also extremely stable over a wide range of temperature and pH.