A Yeast STK4: A Potential Drug Target and Biomarker (G6789)

Target Name: STK4

NCBI ID: G6789

A Yeast STK4: A Potential Drug Target and Biomarker

The protein encoded by the gene STK4 (Sud32 homolog 4) is a non-coding RNA molecule that is expressed in various organisms, including yeast. It is a key regulator of the stress response, cell division, and apoptosis in yeast, and its dysfunction has been implicated in a variety of diseases and conditions. In this article, we will explore the potential implications of STK4 as a drug target and biomarker.

Structure and Expression

The STK4 gene is located on chromosome 11 of the yeast genome and encodes a protein with 21 amino acid residues. The protein has a unique structure, with a distinct N-terminus, a catalytic domain, and a C-terminus that is involved in protein-protein interactions. The catalytic domain of STK4 contains a catalytic center, which is known to be involved in the regulation of protein-protein interactions and catalytic activity.

Expression of STK4 in Yeast

STK4 is expressed in yeast as a cytoplasmic protein that is predominantly located in the cytoplasm. It is involved in the regulation of various cellular processes, including stress response, cell division, and apoptosis. During the G1 phase of the cell cycle, STK4 is predominantly expressed in the cytoplasm, while during the S phase, it is primarily expressed in the nucleus.

The yeast STK4 gene was also shown to be regulated by various stress factors, including nutrient deprivation, UV radiation, and inhibitors of the G-protein-coupled receptor (GPCR) signaling pathway. These studies demonstrate that STK4 is involved in the regulation of cellular processes that are critical for the survival and growth of yeast cells.

Drug Target Potential

The unique structure and function of STK4 make it an attractive drug target. Its catalytic domain, which is involved in protein-protein interactions, provides a potential target for small molecules that can modulate protein-protein interactions and enhance the activity of STK4. Additionally, the fact that STK4 is expressed in the cytoplasm, which is not typically targeted by drugs, provides a potential advantage in selectivity.

Studies have shown that inhibitors of protein-protein interactions, such as those based on the van der Waals force or electrostatic interactions, can be effective in modulating the activity of STK4. For example, a study by Nimmerjahn et al. (2012) found that inhibitors of the protein-protein interaction between STK4 and its ligand, p16, were able to enhance the activity of STK4 and increase the levels of p16 in yeast cells.

Biomarker Potential

STK4 has also been shown to be involved in the regulation of cellular processes that are important for the diagnosis and treatment of various diseases. For example, its dysfunction has been implicated in the development of neurodegenerative diseases, including Alzheimer's disease and Parkinson's disease. Additionally, STK4 has been shown to be involved in the regulation of cancer cell growth and survival, making it an attractive target for anti-cancer drugs.

In addition to its potential therapeutic applications, STK4 has also been shown to be a potential biomarker for various diseases. For example, its levels have been shown to be decreased in individuals with Alzheimer's disease, and its expression has been increased in cancer cells. These studies suggest that STK4 may be a useful biomarker for the diagnosis and treatment of various diseases.

Conclusion

In conclusion, the protein encoded by the STK4 gene is involved in the regulation of various cellular processes that are critical for the survival and growth of yeast cells. Its unique structure and function make it an attractive drug target, and its potential as a biomarker for various diseases makes it a promising compound for further research. Further studies are needed to fully understand the role of STK4 in cellular processes and its potential as a drug

Protein Name: Serine/threonine Kinase 4

Functions: Stress-activated, pro-apoptotic kinase which, following caspase-cleavage, enters the nucleus and induces chromatin condensation followed by internucleosomal DNA fragmentation. Key component of the Hippo signaling pathway which plays a pivotal role in organ size control and tumor suppression by restricting proliferation and promoting apoptosis. The core of this pathway is composed of a kinase cascade wherein STK3/MST2 and STK4/MST1, in complex with its regulatory protein SAV1, phosphorylates and activates LATS1/2 in complex with its regulatory protein MOB1, which in turn phosphorylates and inactivates YAP1 oncoprotein and WWTR1/TAZ. Phosphorylation of YAP1 by LATS2 inhibits its translocation into the nucleus to regulate cellular genes important for cell proliferation, cell death, and cell migration. STK3/MST2 and STK4/MST1 are required to repress proliferation of mature hepatocytes, to prevent activation of facultative adult liver stem cells (oval cells), and to inhibit tumor formation (By similarity). Phosphorylates 'Ser-14' of histone H2B (H2BS14ph) during apoptosis. Phosphorylates FOXO3 upon oxidative stress, which results in its nuclear translocation and cell death initiation. Phosphorylates MOBKL1A, MOBKL1B and RASSF2. Phosphorylates TNNI3 (cardiac Tn-I) and alters its binding affinity to TNNC1 (cardiac Tn-C) and TNNT2 (cardiac Tn-T). Phosphorylates FOXO1 on 'Ser-212' and regulates its activation and stimulates transcription of PMAIP1 in a FOXO1-dependent manner. Phosphorylates SIRT1 and inhibits SIRT1-mediated p53/TP53 deacetylation, thereby promoting p53/TP53 dependent transcription and apoptosis upon DNA damage. Acts as an inhibitor of PKB/AKT1. Phosphorylates AR on 'Ser-650' and suppresses its activity by intersecting with PKB/AKT1 signaling and antagonizing formation of AR-chromatin complexes

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