Biomaterial Database

Differential phospholipid-labeling suggests two subtypes of phospholipase D in rat Leydig cells. 1995

L Lauritzen, and H S Hansen

Department of Biological Sciences, Royal Danish School of Pharmacy, Copenhagen O, Denmark.

The aim of the present study was to compare the transphosphatidylation activity of phospholipase D (PLD) under different substrate labeling conditions, in order to investigate whether PLD in rat Leydig cells exhibited any substrate preferences for the alkyl- or acyl-form of phosphatidylcholine (PtdCho). The [3H]phosphatidylethanol formation in response to 4 beta-phorbol 12-myristate 13-acetate (PMA), sphingosine, or Ca(++)-ionophore A23187, was lower when Leydig cells were labeled with 1-O-[3H]alkyl lysoPtdCho compared with the responses when [3H]myristic acid was employed. In contrast, the results for the receptor agonists (vasopressin, bradykinin, and lysophosphatidic acid), using the two labels, showed more consistency. Thus, the PLD-activity induced by PMA, sphingosine, or A23187 has a more selective substrate range (i.e. mainly acyl-linked PtdCho) than the PLD-activity stimulated via a receptor. Our data suggests the existence of PLD isozymes that differ with respect to substrate specificity and activation mechanisms.

UI	MeSH Term	Description	Entries
D007985	Leydig Cells	Steroid-producing cells in the interstitial tissue of the TESTIS. They are under the regulation of PITUITARY HORMONES; LUTEINIZING HORMONE; or interstitial cell-stimulating hormone. TESTOSTERONE is the major androgen (ANDROGENS) produced.	Interstitial Cells, Testicular,Leydig Cell,Testicular Interstitial Cell,Testicular Interstitial Cells,Cell, Leydig,Cell, Testicular Interstitial,Cells, Leydig,Cells, Testicular Interstitial,Interstitial Cell, Testicular
D008297	Male		Males
D010703	Phorbol Esters	Tumor-promoting compounds obtained from CROTON OIL (Croton tiglium). Some of these are used in cell biological experiments as activators of protein kinase C.	Phorbol Diester,Phorbol Ester,Phorbol Diesters,Diester, Phorbol,Diesters, Phorbol,Ester, Phorbol,Esters, Phorbol
D010739	Phospholipase D	An enzyme found mostly in plant tissue. It hydrolyzes glycerophosphatidates with the formation of a phosphatidic acid and a nitrogenous base such as choline. This enzyme also catalyzes transphosphatidylation reactions. EC 3.1.4.4.	Lecithinase D,Phosphatidylcholine Phosphohydrolase
D010743	Phospholipids	Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.	Phosphatides,Phospholipid
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000001	Calcimycin	An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.	4-Benzoxazolecarboxylic acid, 5-(methylamino)-2-((3,9,11-trimethyl-8-(1-methyl-2-oxo-2-(1H-pyrrol-2-yl)ethyl)-1,7-dioxaspiro(5.5)undec-2-yl)methyl)-, (6S-(6alpha(2S,3S),8beta(R*),9beta,11alpha))-,A-23187,A23187,Antibiotic A23187,A 23187,A23187, Antibiotic
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013110	Sphingosine	An amino alcohol with a long unsaturated hydrocarbon chain. Sphingosine and its derivative sphinganine are the major bases of the sphingolipids in mammals. (Dorland, 28th ed)	4-Sphingenine,4 Sphingenine
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities