Neuroscience

G-protein coupled receptor 78 (GPR78) was identified based on homology to other GPCR family members. The GPR78 gene encodes an orphan receptor protein that is 363 amino acids in length and contains the typical seven transmembrane domain found in GPCRs. The protein is widely expressed in the mammalian brain including the pituitary and is also found in the placenta. While a ligand for GPR78 has yet to be identified, its expression pattern suggests a potential role in hormone and stress regulation as well as during pregnancy.

PTEN-induced putative kinase 1 (PINK1) is a serine/threonine kinase with important functions in mitochondrial quality control. Together with the Parkin protein, PINK1 is able to regulate the selective degradation of damaged mitochondria through autophagy. Normally PINK1 is imported into the mitochondria where it is targeted for proteolytic cleavage. This cleavage event results in unstable products and is the reason PINK1 is difficult to detect in healthy mitochondria.

Heat shock cognate 71 kDa protein (Hsc70), also known as HSPA8, is a member of the heat shock protein 70 family (Hsp70). Unlike Hsp70, it is a constitutively expressed chaperone protein and is involved in diverse cellular processes including protein folding and protein degradation. Hsc70 consists of two domains: the nucleotide binding domain (NBD) and the substrate binding domain (SBD). Hsc70, with the help of accessory proteins, exerts its chaperone activity by binding to short hydrophobic stretches of nascent or unfolded polypeptides through the SBD in an ATP-dependent manner.

What is the Cellular Role of the CD11 Protein?

The CD11 protein is actually a heterodimer complex that consists of CD11b and CD18. CD11 is involved in numerous adhesion-related associations between cells such as monocytes, macrophages, natural killer (NK) cells, and granulocytes. CD11 also regulates the uptake of complement-coated particles within cells. It has also gained usage as a microglial marker for tissues derived from the nervous system.

The protein P2Y2 is a G-protein coupled metabotropic receptor that belongs to a larger family consisting of several receptor subtypes that each has a different pharmacological selectivity for various adenosine and uridine nucleotides. (This selectivity overlaps in some cases).

The thymidine synthetic nucleoside analogue bromodeoxyuridine (BrdU) has a long, colorful history of repeated use in molecular and cytokinetic studies, as detailed in reviews by Vanderlaan and Dolbeare (1,2).  Because BrDU is only incorporated into newly synthesized DNA in actively replicating S-phase cells, it allows for accurate and comprehensive quantitation of the pattern, rate, and progression of cell proliferation.

CD90 is a 25-35kD glycosylphosphatidylinositol (GPI)-linked glycoprotein receptor of the immunoglobulin (Ig) superfamily. It is found on murine T-cells, thymocytes, neuronal cells, granulocytic lineage-derived cells, hematopoietic stem cells, fibroblasts, neurons, and Kupffer's cells. CD90 is often used as a marker for a variety of stem cells and mature neuronal axon processes.  CD90 appears to play a role in cell-cell and cell-matrix interactions and adhesion during synaptogenesis, nerve regeneration, apoptosis and necrosis, inflammation, fibrosis, and metastasis.

The protein PINK1 is a mitochondrial-located serine/threonine kinase (PTK) that maintains organelle function and integrity. It not only protects organelles from cellular stress, but it also uses the selective auto-phagocytosis process for cleaning and clearing cell damage. Exner et al initially reported that, in humans, a PINK1 deficiency is linked to autosomal recessive incidences of both neurodegenerative pathology and Parkinson's Disease (PD) (1).

The Beta III tubulin protein is abundantly present in both the central and peripheral nervous systems (CNS and PNS), where it is predominantly expressed during fetal and postnatal development. In cerebellar and sympathoadrenal neurogenesis, Beta III distribution is neuron-associated and present in distinct temporal-spatial gradients that are dictated by the regional neuroepithelia of origin.

PINK1 (PTEN induced putative kinase 1) is a mitochondrial serine/threonine kinase which maintains mitochondrial function/integrity, provides protection against mitochondrial dysfunction during cellular stress, potentially by phosphorylating mitochondrial proteins, and is involved in the clearance of damaged mitochondria via selective autophagy (mitophagy).