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The La protein is a 47 kDa polypeptide that frequently acts as an autoantigen in systemic lupus erythematosus and Sjogren's syndrome patients. La is involved in various aspects of RNA metabolism, including binding and protecting 3-prime UUU(OH) elements of newly RNA polymerase III - transcribed RNA, processing 5-prime and 3-prime ends of pre-tRNA precursors, acting as an RNA chaperone, and binding viral RNAs linked to hepatitis C virus. It occurs in both the nucleus and the cytoplasm, where it assumes different roles. In the nucleus, La protein facilitates the production of tRNAs, acting as an RNA polymerase III (RNAP III) transcription factor by attaching to the U-rich 3'UTR of nascent transcripts, aiding in their folding and maturation. In the cytoplasm, La protein facilitates the translation of specific mRNAs, acting as a translation factor. As an RNA binding protein (RBP), La protein associates with subsets of mRNAs which contain a 5'-terminal oligopyrimidine (5'TOP) motif known to direct protein synthesis. The binding of La protein to particular classes of RNA molecules regulates their downstream processing, guards them from endonuclease digestion, and organizes their export from the nucleus. La/SS-B appears to be readily disposed to proteolysis, which results in many smaller (42kD, 320, and 270) nevertheless still immunoreactive polypeptides. La/SS-B antigen is strongly conserved across species. Anti-La/SS-B autoantibodies were originally found as precipitating autoantibodies in sera of Sjogren's Syndrome patients and referred to as SjT. Anti-La/SS-B precipitins are most frequently found in Sjogren's Syndrome, Systemic Lupus Erythematosus (SLE) and Subacute Cutaneous Lupus. Also, there seems to be a correlation between anti-La/SS-B and the absence of nephritis in SLE patients.

Thiosulfate sulfurtransferase like domain containing 1 (TSTD1) is a member of a family of transferases, specifically the sulfurtransferases, which transfer sulfur-containing groups. TSTD1 is localized around the nuclear membranes. TSTD1 is expressed in a number of human tissues, including the kidney, liver, skeletal muscle, heart, colon, thymus, spleen, placenta and lung. TSTD1 may participate in cyanide detoxification, the formation of iron-sulfur proteins, and the modification of sulfur-containing enzymes.

Reticulocalbin-2 (RCN2) is a member of the CREC protein family. RCN2 is a calcium-binding protein found in the lumen of the ER. RCN2 contains 6 conserved regions with similarity to a high affinity Ca(+2)-binding motif, the EF-hand.

A human infecting coronavirus (viral pneumonia) called 2019 novel coronavirus, 2019-nCoV was found in the fish market at the city of Wuhan, Hubei province of China on December 2019.

The 2019-nCoV shares an 87% identity to the 2 bat-derived severe acute respiratory syndrome 2018 SARS-CoV-2 located in Zhoushan of eastern China. 2019-nCoV has an analogous receptor-BD-structure to that of 2018 SARS-CoV, even though there is a.a. diversity so thus the 2019-nCoV might bind to ACE2 receptor protein (angiotensin-converting enzyme 2) in humans.

While bats are possibly the host of 2019-nCoV, researchers suspect that animal from the ocean sold at the seafood market was an intermediate host. RSCU analysis proposes that the 2019-nCoV is a recombinant within the viral spike glycoprotein between the bat coronavirus and an unknown coronavirus.

Since April 2012, cases of the Middle East Respiratory Syndrome Coronavirus (MERS-CoV) have been identified in various countries. Coronaviruses are the cause of the common cold, SARS (severe acute respiratory syndrome) and other severe illnesses with high mortality rates, all are classified into coronavirus family. MERS-CoV is a new type of SARS found in the coronavirus family causing severe pneumonia with sudden and serious respiratory illness with high mortality rates as well. Since January 27th 2015, the WHO has reported 956 human cases, including 351 deaths. More cases of the new coronavirus strain are expected. Like in other coronaviruses, large surface spike glycoprotein is a central structural protein of this virus; it is located above the virion surface to bind and enter into the target cell. Spike protein has 2 domains- S1 and S2. The S1 domain is responsible for cellular tropism and interaction with target cell, while the S2 domain is responsible for membrane fusion. The C-terminal of S1 domain contains a receptor binding domain, and is also a potential target for vaccine development and an antigen for diagnosis.

AHSG (fetuin-A) which is a glycoprotein present in the serum, is synthesized by hepatocytes. AHSG is one of the fetuin class of plasma binding proteins. It is involved in a number of functions, such as endocytosis, brain development and the formation of bone tissue. It is usually present in the cortical plate of the immature cerebral cortex and bone marrow hemopoietic matrix, hence it has been postulated that it participates in the development of the tissues. Yet, its exact significance is still vague. AHSG promotes endocytosis, hold opsonic properties and influences the mineral phase of the bone. Affinity for calcium and barium ions has been shown.

DDX39A which is a part of the DEAD box protein family is characterized by the conserved motif Asp-Glu-Ala-Asp. This pattern is implicated in a various cellular processes involving alteration of RNA secondary structure, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. Several members of the DEAD box protein family are taking part in embryogenesis, spermatogenesis, and cellular growth and division.

Asialoglycoprotein Receptor 2 (ASGR2) is a hetero-oligomeric protein comprised of major and minor subunits, encoded by different genes. ASGR2 is a subunit of the asialoglycoprotein receptor; it is the less abundant minor subunit. The ASGR2 receptor is a transmembrane protein, which has a crucial role in serum glycoprotein homeostasis by mediating the endocytosis and lysosomal degradation of glycoproteins with exposed terminal galactose or N-acetylgalactosamine residues.

EDF1 controls endothelial cell differentiation. EDF1 has a role as a bridging protein that interconnects regulatory proteins and the basal transcriptional machinery, thus modulating the transcription of genes that take part in endothelial differentiation. EDF1 binds calmodulin through its IQ domain and controls nitric oxide synthase activity via calmodulin sequestration in the cytoplasm. EDF1 is localized in adult liver, heart, adipose tissues, intestine and pancreas.

Neuregulin/Heregulin is a family of structurally related polypeptide growth factors which are stemmed from alternatively spliced genes (NRG1, NRG2, NRG3 and NRG4). There are more than 14 soluble and transmembrane proteins derived from the NRG1 gene. Proteolytic processing of the extracellular domain of the transmembrane NRG1 isoforms release soluble growth factors. These isoforms contain the heregulins (HRGs), glial growth factors (GGFs) and sensory and motor neuron-derived factor (SMDF). All these factors have the Ig and EGF-like domain, and are able to bind to ErbB3 and ErbB4 receptor tyrosin kinases. This binding stimulates erb3 and erb4 heterodimerization with erb2, promoting intrinsic kinase activity, which results in tyrosine phosphorylation. NRG1 isoforms induce the growth and differentiation of epithelial, neuronal, glial, and other types of cells.

Odd-Skipped Related Transcription Factor 2, also know as OSR2 belongs to the Odd C2H2-type zinc-finger protein family. OSR2 is a mammalian homolog of the Drosophila odd-skipped family of transcription factors.

KLF4 is a transcription factor that performs as both an activator and repressor. KLF4 is expressed mainly in erythroid tissues and found mostly in gut. KLF4 is takes part in the differentiation of epithelial cells in addition to skeletal and kidney development.

Kruppel-Like Factor 7 (KLF7) is a part of the Kruppel-like transcriptional regulator family whose members regulate cell proliferation, differentiation and survival and contain 3 C2H2 zinc fingers at the C-terminus that mediate binding to GC-rich sites. KLF7 contributes to the progression of type 2 diabetes by inhibiting hormone expression and secretion in pancreatic beta-cells and also by deregulating adipocytokine secretion in adipocytes.

Galectins are a family of animal lectins with an affinity for beta-galactosides. This family has at least 14 identified members. Galectins share similarities in the CRD (the carbohydrate recognition domain). Galectins are synthesized as cytosolic proteins. Though localized principally in the cytoplasm and lacking a classical signal peptide, galectins can also be stimulated to secretion by non-classical pathways or alternatively targeted to the nucleus. Galectins are involved in modulating cell-cell and cell-matrix interactions. Human Galectin-7 belongs to the prototypical Galectins containing a single CRD, which is initially identified in human epidermis as a monomer. The Galectin-7 expression is induced by tumor suppressor protein p53 and associated with apoptosis. Galectin-7 is a pro-apoptotic protein which functions intracellularlly upstream of JNK activation and mitochondrial cytochrome c release. The correlation of Galectin-7 with the UV-induced apoptosis of keratinocytes presents a critical mechanism in the maintenance of epidermal homeostasis. Human Galectin-7 is localized in both nucleus and cytoplasm.

Protease Serine 7, also known as PRSS7, is in charge of initiating the activation of pancreatic proteolytic proenzymes such as trypsin, chymotrypsin and carboxypeptidase A. PRSS7 catalyzes the conversion of trypsinogen to trypsin which in turn activates other proenzymes including chymotrypsinogen, procarboxypeptidases, as well as proelastases.

LSM2 is a member of the snRNP Sm proteins family. Sm-like proteins are branded in several organisms based on sequence homology with the Sm protein family. Sm-like proteins hold the Sm sequence motif that is made up of 2 regions separated by a linker of variable length which folds as a loop. The Sm-like proteins are believed to create a steady heteromer present in tri-snRNP particles, which are vital for pre-mRNA splicing. LSM2 binds specifically to the 3'-terminal U-tract of U6 snRNA nad takes part in pre-mRNA splicing.

Clusterin also named Apolipoprotein J (APO-J) is a 75-80 kD disulfide-linked heterodimeric protein containing about 30% of N-linked carbohydrate rich in sialic acid but truncated forms targeted to the nucleus have also been identified.
The precursor polypeptide chain is cleaved proteolytically to remove the 22-mer secretory signal peptide and subsequently between residues 227/228 to generate the a and b chains. These are assembled in anti-parallel to give a heterodimeric molecule in which the cysteine-rich centers are linked by five disulfide bridges and are flanked by two predicted coiled-coil a-helices and three predicted amphipathic a-helices.
Across a broad range of species clusterin shows a high degree of sequence homology ranging from 70% to 80%. It is nearly ubiquitously expressed in most mammalian tissues and can be found in plasma, milk, urine, cerebrospinal fluid and semen.
It is able to bind and form complexes with numerous partners such as immunoglobulins, lipids, heparin, bacteria, complement components, paraoxonase, beta amyloid, leptin and others. Clusterin has been ascribed a plethora of functions such as phagocyte recruitment, aggregation induction, complement attack prevention, apoptosis inhibition, membrane remodeling, lipid transport, hormone transport and/or scavenging, matrix metalloproteinase inhibition.
A genuine function of clusterin has not been defined. One tempting hypothesis says that clusterin is an extracellular chaperone protecting cells from stress induced insults caused by degraded and misfolded protein precipitates.
Clusterin is up- or down regulated on the mRNA or protein level in many pathological and clinically relevant situations including cancer, organ regeneration, infection, Alzheimer disease, retinitis pigmentosa, myocardial infarction, renal tubular damage, autoimmunity and others.

General Transcription Factor IIF Polypeptide 2 (GTF2F2) is a general transcription initiation factor which binds to RNA polymerase II and helps engage it in the initiation complex in collaboration with TFIIB. GTF2F2 promotes transcription elongation. GTF2F2 shows ATP-dependent DNA-helicase activity.

Ribosomes are the organelles which catalyze protein synthesis, they’re comprised of a small 40S subunit and a large 60S subunit. Ribosomal Protein L11 (RPL11) is a member of the L5P family of ribosomal proteins. RPL11 is a ribosomal protein which is a component of the 60S subunit. RPL11 is found in the cytoplasm. The RPL11 protein most likely associates with the 5S rRNA.

Ribosomes, the organelles which catalyze protein synthesis, contain a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and nearly 80 structurally different proteins. RPL35A is a component of the 60S subunit of the ribosomal protein and a member of the L35AE family of ribosomal proteins. RPL35A is situated in the cytoplasm. The rat protein is known to bind to both initiator and elongator tRNAs, therefore, it is located at the P site, or P and A sites, of the ribosome. Though RPL35A was initially mapped to chromosome 18, it has been proven that it is located at 3q29-qter. Transcript variants utilizing alternative transcription initiation sites and alternative polyA signals exist. As is typical for genes encoding ribosomal proteins, there are several processed pseudogenes of this gene spread all over the genome.

Secreted frizzled-related protein 4 (SFRP4) belongs to the SFRP family which contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzled proteins. SFRPs serve as soluble modulators of Wnt signaling. SFRP4 may serve as a regulator of adult uterine morphology and function. SFRP4 increases apoptosis during ovulation possibly via modulation of FZ1/FZ4/WNT4 signaling. SFRP4 also has phosphaturic effects by specifically inhibiting sodium-dependent phosphate uptake. SFRP4 is expressed in proliferative endometrium and several types of ovarian, endometrial and Brest tumors. SFRP4 is expressed in mesenchymal cells and in cardiomyocytes. SFRP4 expression in ventricular myocardium correlates with apoptosis related gene expression. SFRP4 is up-regulated in failing myocardium.

Adaptor-related protein complex 1 associated regulatory protein (AP1AR) is essential for AP-1 dependent transport between the trans-Golgi network and endosomes. AP1AR regulates the membrane association of AP1G1/Gamma1-adaptin which is one of the subunits of the AP-1 adapter complex. AP1AR plays a role as effector of AP-1 in calcium-induced endo-lysosome secretion. The interaction with AP1G1/Gamma1-adaptin attenuates the release of the AP-1 complex from membranes.

EXOSC1 is a non-catalytic component of the exosome which has 3'->5' exoribonuclease activity and participates in many cellular RNA processing and degradation occasions. EXOSC1 associates with the exosome by protein-protein interactions with ribosomal RNA-processing protein 42 and ribosomal RNA-processing protein 46.

Exosome Component 3 (EXOSC3) is a non-catalytic component of the human exosome, a complex with 3'-5' exoribonuclease activity. EXOSC3 takes part in various RNA processing and degradation activities including degradation of histone mRNA. Linked pseudogenes of EXOSC3 are located on chromosome 19 and 21.