Esterase

YOD1 is a Hydrolase which removes conjugated ubiquitin from proteins and takes part in endoplasmic reticulum-associated degradation (ERAD) for misfolded lumenal proteins. YOD1 is a highly conserved deubiquitinating enzyme belonging to the ovarian tumor (otubain) family, whose function has yet to be determined in mammalian cells. YOD1 is a component of a multiprotein complex with p97 as its nucleus, proposing a functional link to a pathway responsible for the dislocation of misfolded proteins from the endoplasmic reticulum. YOD1 variant xpression deprived of its deubiquitinating activity compels a halt on the dislocation reaction, as concluded by the stabilization of various dislocation substrates.

Carboxylesterase 1 (CES1G) belongs to a large family of carboxylesterases that are liable for the hydrolysis of ester and amide bonds. CES1G is also participates in the detoxification of xenobiotics prodrugs. CES1G shares the serine hydrolase fold observed in other esterases. CES1G found in rats and mice and is expressed mainly in liver, but also in kidney and lung.

Carboxylesterase 1D, also known as CES1D is part of a big family of carboxylesterases which are responsible for the hydrolysis of ester in addition to amide bonds. CES1D is the principle lipase of white adipose tissue fat cake extracts. Partially purified white adipose tissue Ces1d had lipase activity in addition to lesser but detectable neutral cholesteryl ester hydrolase activity. CES1D demonstrates low catalytic efficiency for hydrolysis of CPT-11, a prodrugs for camptothecin used in cancer therapeutics.

CES1 is a part of the alpha/beta fold hydrolase familyand participates in the detoxification of xenobiotics and in the activation of ester and amide prodrugs. CES1hydrolyzes aromatic and aliphatic esters, although it has no catalytic activity toward amides or a fatty acyl-CoA ester. CES1hydrolyzes the methyl ester group of cocaine to form benzoylecgonine and catalyzes the transesterification of cocaine to form cocaethylene. CES1also plays a role in detoxification in the lung and protection of the central nervous system from ester or amide compounds.CES1 is found in most tissues, mainly in the liver.

PPME1 catalyzes the demethylation and inactivation of protein phosphatase (PP2A), a multimeric phosphoserine/ threonine protein phosphatase related to growth inhibition and cell cycle arrest. PPME1 can demethylate PP2A catalytic subunit in vitro and okadaic acid treatment can inhibit this reaction. It is conserved from yeast to human and holds a motif found in lipases having a catalytic triad activated serine as their active site nucleophile.

Tyrosyl-DNA Phosphodiesterase 2 (TDP2), belongs to the CCR4/nocturin family of divalent cation-dependent phosphodiesterases.TDP2 associates with CD40, tumor necrosis factor (TNF) receptor-75 and TNF receptor associated factors (TRAFs), and inhibits nuclear factor-kappa-B activation. TDP2 is characterized by similar sequence and structure as APE1 endonuclease, which participates in DNA repair and the activation of transcription factors.

Tyrosyl-DNA phosphodiesterase 1 ( TDP1) is required for repairing stalled topoisomerase I-DNA complexes by catalyzing the hydrolysis of the phosphodiester bond between the tyrosine residue of topoisomerase I and the 3-prime phosphate of DNA. TDP1 also detach glycolate from single-stranded DNA having 3-prime phosphoglycolate, suggesting a role in repair of free-radical mediated DNA double-strand breaks.

PDE6H belongs to the rod/cone cGMP-PDE gamma subunit family, which selectively catalyze the hydrolysis of 3 cyclic phosphate bonds in adenosine and/or guanine 3,5 cyclic monophosphate (cAMP and/or cGMP). This family regulates the cellular levels, localization and duration of action of these second messengers by controlling the rate of their degradation. PDE6H is the inhibitory (or gamma) subunit of the cone-specific cGMP phosphodiesterase, which is atetramer composed of two catalytic chains (alpha and beta), and two inhibitory chains (gamma). PDE6H is particularly expressed in the retina, and is implicated in the transmission and amplification of the visual signal. Mutations in PDE6H have been associated with retinal cone dystrophy type 3A.

Human PDE6D was initially identified as a fourth subunit of rod-specific cGMP phosphodiesterase, PDE6. PDE6D is an Oligomer composed of two catalytic chains (alpha and beta), an inhibitory chain (gamma) and the delta chain. PDE6D interacts with RPGR, ARL2 and ARL3. The catalytically active PDE6 is a heterodimer (αβ) that is controlled by two inhibitory γ subunits. Since PDE6D does not change the catalytic properties of PDEαβ, its function is still unanswered. PDE6D is expressed specifically in the retina.

Formylglutathione hydrolase (Esterase D) is a member of the esterase D family. Esterase D is a serine hydrolase involved in the detoxification of formaldehyde. Esterase D is active toward various substrates including O-acetylated sialic acids, and it may possibly be involved in the recycling of sialic acids. Esterase D is used as a genetic marker for retinoblastoma and Wilson's disease.

Acyl-CoA Thioesterase 8 (ACOT8) is a group of enzymes which catalyze the hydrolysis of acyl-CoAs to the free fatty acid and coenzyme A (CoASH), granting the potential to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. ACOT8 mediate Nef-induced down-regulation of CD4. ACOT8 contends with BAAT (Bile acid CoA: amino acid N-acyltransferase) for bile acid-CoA substrate (such as chenodeoxycholoyl-CoA). ACOT8 prefers medium-length fatty acyl-CoAs.

Acyl-CoA Thioesterase 7 (ACOT7) belongs to the acyl coenzyme family. ACOT7 hydrolyzes the CoA thioester of palmitoyl-CoA and other long-chain fatty acids. Decreased expression of the ACOT7 protein may be linked to mesial temporal lobe epilepsy.

Acyl-coenzyme A thioesterase 13 (ACOT13) belongs to the thioesterase subfamily of esterase family. ACOT13 is highly expressed in the kidney with moderate expression in the brain, liver and intestines. ACOT13 contains a hotdog-fold and is thought to co-localize with microtubules, possibly having a role in cellular proliferation events. Deletion of a segment of the q arm of chromosome 6 is linked to early onset intestinal cancer, suggesting the presence of a cancer susceptibility locus.

ACOT11 belongs to the acyl-CoA thioesterase family which catalyses the transformation of activated fatty acids to the equivalent non-esterified fatty acid and coenzyme A. Expression of a mouse homolog in brown adipose tissue is induced by low temperatures and inhibited by high temperatures. Obesity-resistant mice demonstrated High levels of expression compared with obesity-prone mice, indicating BFIT takes part in acyl-CoA thioesterase 11 in obesity. BFIT has acyl-CoA thioesterase activity towards medium (C12) and long-chain (C18) fatty acyl-CoA substrates.

Acetylcholinesterase (ACHE) belongs to the type-B carboxylesterase/lipase family. ACHE catalyzes the breakdown of acetylcholine and other choline esters that play a role as neurotransmitters. During neurotransmission, ACH is released from the presynaptic neuron into the synaptic cleft and binds ACH receptors on the post-synaptic membrane, transmitting the signal from the nerve. ACHE is located on the post-synaptic membrane, terminates the signal transmission by hydrolyzing ACH.