The G1/S cell cycle checkpoints control whether eukaryotic cells enter the S phase (synthesis phase) of DNA synthesis after having properly completed the G1 phase to ensure the cell has enough energy and resources to begin DNA replication. Two cell cycle kinase complexes, CDK4/6-Cyclin D and CDK2- Cyclin E, work together to relieve the inhibition of dynamic transcriptional complexes containing retinoblastoma protein (Rb) and E2F. In cells undefined during the G1 phase, hypophosphorylated Rb binds to the E2F-DP1 transcription factor and forms an inhibitory complex with HDAC, thereby inhibiting downstream key transcriptional activities. Clear entry into the S phase is achieved by continuous phosphorylation of Rb by Cyclin D-CDK4/6 and Cyclin E-CDK2, which separates the transcription factor E2F from the inhibitory complex and allows transcription of the gene required for DNA replication. After the growth factor disappears, the expression level of cyclin D is down-regulated by down-regulation of protein expression and phosphorylation-dependent degradation. Without a proper G1/S checkpoint, the cell could arrest or potentially undergo aberrant processes that could lead to disease states such as cancer.

Embryonic stem cells (ES cells) are pluripotent stem cells isolated from an inner cell mass of early-stage embryo-blastocysts. ES cells have a high differentiation potential., which means that they have the capacity to develop into whatever cell type the body needs depending on the signals received by the ES cell. At the same time, while ES cells are undifferentiated, they retain the potential to infinitely replicate, making them highly attractive and renewable subjects for targeted cell therapy and regenerative medicine.

Cluster of differentiation, or CD molecules, are cell surface markers that are used for identification of cell types in pathology and other bioscience disciplines. The expression levels of CD markers may increase or decrease (or disappear altogether, at least to undetectable levels) when cells (for example, leukocytes, red blood cells, platelets, and vascular endothelial cells, etc.) differentiate into new and different lineages. Depending on the CD marker, the expression level may identify a phenotype for different segments of cells, such as when they become active or diseased. Most CD molecules are transmembrane proteins or glycoproteins, including extracellular regions that bind a ligand or opposing receptor, transmembrane regions to anchor the CD marker into the cell, and cytoplasmic regions that may confer some adaptor or catalytic function. Some CD molecules can also be "anchored" on the cell membrane by means of inositol phospholipids. A few CD molecules are carbohydrate haptens. The study of CD molecules can be used in many basic immunology research fields, such as the relationship between CD antigen structure and function, cell activation pathway, signal transduction and cell differentiation, etc. It can be used clinically for disease mechanism research, clinical diagnosis, disease prognosis, efficacy tracking and treatment, and more. CD molecules such as CD4, CD8, CD25, etc. can be used to identify populations of cells when studying samples by flow cytometry or immunofluorescence.

The Hippo signal is very conservative in evolution. It regulates organ size and tissue stability by regulating cell proliferation, apoptosis, and stem cell renewal. The core process of Hippo signaling is a kinase tandem process, Mst1/2 and Sav1 form a complex, phosphorylate and activate Lats1/2; Lats1/2 kinase then phosphorylates and inhibits transcriptional coactivators Yap and Taz. Yap and Taz are the most important effectors downstream of the Hippo pathway. Upon dephosphorylation, Yap and Taz translocate to the nucleus and interact with TEAD1-4 or other transcription factors (such as CTGF) to induce gene expression, thereby initiating cell proliferation and inhibiting apoptosis.

The glyceraldehyde-3-phosphate dehydrogenase, or GAPDH for short), is a multifunctional, indispensable enzyme found in all cells. The generally known function of GAPDH is to assist in carbohydrate metabolism as a key player in glycolysis, but there are studies demonstrating its role in the nucleus as well. 

GAPDH is a constitutively expressed housekeeping protein, and GAPDH mRNA levels and protein levels are often used as loading controls in experiments that quantify target-specific expression changes. Recent studies have elucidated the role of GAPDH in apoptosis, gene expression through its possible activities as a transcription factor, and nuclear transport. As both a metabolic protein as well as one that might play a role in cytoskeletal reorganization, GAPDH activity is intricately tied to tumorigenesis. GAPDH may also play a role in neurodegenerative diseases such as Huntington's disease and Alzheimer's disease. Therefore, although many researchers do use GAPDH as a control, this protein needs to be appreciated for its myriad other functions as well!

ABclonal Technology's GAPDH recombinant rabbit monoclonal antibody is a human-specific antibody that can be used with a high dilution ratio of 1:2560000. As a highly-stable antibody product, this means that you can perform numerous Western blotting experiments over a long period of time using a small quantity of antibody, as well as in other experiments to study the functions of GAPDH. Take advantage of this robust, cost-effective antibody product in your research today!

Long-interspersed nuclear elements (LINEs) are genetic components found in higher eukaryotes. They are retrotranposons, meaning that they are transcribed into mRNA and then translated into proteins that act as a reverse transcriptase. The reverse transcriptase makes a copy of the LINE DNA which can then be integrated into the genome at a new site. The only active LINE in humans is LINE-1. It has been associated with oncogenesis and Haemophilia A, a diseased caused by insertional mutagenesis.