prostaglandin D synthase 1; prostaglandin-H2 D-isomerase; glutathione-independent PGD synthetase; beta-trace protein; lipocalin-type PGD synthase; L-PGDS (PTGDS)

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Function

one of 2 enzymes that catalyzes formation of PGD2 from PGH2
lipocalin-type, glutathione independent
binds small non-substrate lipophilic molecules, including biliverdin, bilirubin, retinal, retinoic acid & thyroid hormone
may act as a scavenger for harmful hydrophopic molecules
secretory retinoid & thyroid hormone transporter (putative)
role in development & maintenance of barriers (putative)
- blood-brain barrier
- blood-retina barrier
- blood-aqueous humor barrier
- blood-testis barrier
roles in both maturation & maintenance of the central nervous system & male reproductive system (putative)

both N-glycosylation recognition sites are almost quantitatively occupied by N-glycans of the biantennary complex type, with a considerable proportion of structures bearing a bisecting GlcNAc
agalacto structure as well as sialylated & nonsialylated oligosaccharides bearing alpha2-3- &/or alpha2-6-linked neuNAc are present
belongs to the calycin superfamily, lipocalin family

abundant in the brain & CNS
expressed in tissues of the blood-brain barrier & secreted into cerebrospinal fluid
abundantly expressed in heart
in the male reproductive system, expressed in testis, epididymis & prostate, & is secreted into the seminal fluid
expressed in the eye & secreted into the aqueous humor
lower levels detected in various tissue fluids such as serum, normal urine, ascitic fluid & tear fluid
also found in a number of other organs including ovary, fimbriae of the fallopian tubes, kidney, leukocytes
expression in the amniotic fluid increases during weeks 12 to 25 of pregnancy; levels decrease slowly after 25 weeks
induced by IL-1 beta & thyroid hormone
probably induced by dexamethasone, dihydrotestosterone, progesterone, retinoic acid & retinal
repressed by the notch-Hes signaling pathway

urinary & serum levels of PTGDS may be an indicator of renal damage in diabetes mellitus & hypertension
elevated levels in the coronary circulation may also be associated with angina pectoris
changes in charge & molecular weight microheterogeneity, due to modification of the N-linked oligosaccharides, may be associated with neurodegenerative disease & multiple sclerosis
detected in meningioma but not in other brain tumors; may be a specific cell marker for meningioma
expression levels in amniotic fluid are altered in abnormal pregnancies; levels are lower in pregnancies with trisomic fetuses & fetuses with renal abnormalities