Antibody catalog

UV resistance-associated gene (UVRAG) is a tumor suppressor that is commonly mutated in colon and breast cancer. While UVRAG was discovered for its ability to complement UV sensitivity in xeroderma pigmentosum cells, its main functions are in autophagy, endocytosis, and apoptosis. During autophagy UVRAG interacts with Beclin 1 to promote autophagosome formation. UVRAG can also interact with VPS16 to recruit membrane fusion machinery to mediate autophagosome maturation.

Catecholamines are tyrosine-derived hormones that are produced in the adrenal gland. They include epinephrine, norepinephrine, and dopamine and are used as neurotransmitters by the central and peripheral nervous system. The rate limiting enzyme in catecholamine synthesis is Tyrosine Hydroxylase. Tyrosine Hydroxylase is responsible for the conversion of tyrosine to L-DOPA, which is readily converted into dopamine. Epinephrine and Norepinephrine are then further derived from dopamine.

Transcription factor EB (TFEB) is a member of the MiTF/TFE (Microphthalmia/TFE) subfamily of basic/helix-loop-helix/leucine zipper transcription factors. This group of proteins is involved in the proliferation and development of specific cell types such as osteoclasts or melanocytes. Recently scientists have begun to uncover the roles of MiTF/TFE proteins in organelle biogenesis and energy metabolism (1). TFEB, for example, is a known regulator of lysosome biogenesis.

The tau protein is a microtubule associated protein found mostly in neuronal cells where it regulates the stability of axonal microtubules as well as kinesin-dependent transport. Tau is relevant in the study of various neurological disorders as abnormal post translational modifications can alter its structure and lead to protein aggregates. Tau is present on microtubules in neuronal cells and is also associated with the plasma membrane.

WD repeat domain phosphoinositide-interacting protein 1 (WIPI) is involved in the lysosomal degradation of cytoplasmic components during starvation-induced autophagy. WIPI1 is a seven bladed beta-propeller protein that provides a scaffold for the assembly of multimeric protein complexes (1). During the assembly of the autophagosome WIPI1 interacts with the lipid phosphatidylinositol-3 phosphate (PI3P) and mediates the recruitment of the large multimeric complex of ATG12-ATG5-ATG16 (1).

VPS34, vacuolar protein sorting 34, is the only identified Class III phosphoinositide-3 kinase (PI3K) in mammals and is ubiquitously expressed in all eukaryotic cells. VPS34 is a 100 kDa protein responsible for phosphorylating phosphatidylinositol to produce phosphatidylinositol 3-phosphate (PI3P). PI3P is an important intermediate in the development of the double-membraned autophagosome during autophagy, indicating a role for VPS34 in autophagy initiation. PI3P allows VPS34 to form complexes with ATG14L during the elongation of the autophagosome membrane.

Autophagy is an important cellular process involved in degradation and recycling of cellular macromolecules in response to stress or starvation. Autophagy is carried out in four main phases: phagophore nucleation, autophagosome elongation, docking and fusion with a lysosome, and vesicle breakdown and degradation. ULK1, also known as UNC51-like autophagy activating kinase 1, is a 112 kDa protein with serine-threonine kinase activity. ULK1 is one of two mammalian homologues of the yeast ATG1 kinase, known for its role in autophagy initiation (1).

S6K is a serine/threonine kinase that is a member of the ribosomal S6 kinase (RSK) family. S6K exists in two main isoforms, S6K1 and S6K2, which can also be alternatively spliced to produce different splice forms. S6K1 has two major splicing products that are approximately 70 kDa and 85 kDa, known as p70S6K and p85S6K respectively. S6K is activated via phosphorylation by mTORC1 which relieves the autoinhibition of S6K. Active S6K phosphorylates the ribosomal S6 protein, which induces protein synthesis and cell growth and proliferation.

Autophagy is an important cellular process that maintains homeostasis by degrading and recycling damaged proteins and organelles. Autophagy receptors, such as p62/SQSTM1, recognize these intracellular cargo and mediate their engulfment by the double-membrane autophagosome. The autophagosomes are subsequently targeted to the lysosome for degradation. An early regulatory step in this process is the activation and lipidation of ATG8 related proteins such as microtubule-associated protein-1 light chain 3 (LC3).

Membrane fusion is an essential step during the trafficking of endosomes and vesicles throughout the cell. Membrane fusion events are facilitated by multisubunit tethering complexes (MTC) including CORVET and HOPS. These complexes interact with Rab GTPases and SNARE proteins to promote the fusion of endosomes and lysosomes (1). In yeast VPS41 is a component of the HOPS complex that is needed for transport of endosomes and Golgi-derived vesicles to the vacuole. The choice between these two substrates is facilitated by the phosphorylation of VPS1 by Yck3 (2). Carbrera et al.