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M Puder

Publications and source records attributed to M Puder.

13 recordsLinked to original sources
PubMed1997

Glutathione conjugates recognize the Rossmann fold of glyceraldehyde-3-phosphate dehydrogenase.

Leukotriene (LT) C4 and other glutathione conjugates are synthesized intracellularly and then move to the plasma membrane for export. The intracellular proteins that bind these molecules and the significance of these interactions are poorly understood. To identify the binding sites of membrane-associated proteins that recognize these molecules, we utilized photoaffinity probes to label the inner leaflet of erythrocytes. The predominant molecule labeled with S-(p-nitrobenzyl)glutathione-[125I]4-azidosalicylic acid (PNBG-[125I]ASA) or LTC4-[125I]4-azidosalicylic acid (LTC4-[125I]ASA) was 38 kDa. The protein was labeled with PNBG-[125I]ASA, electroblotted to polyvinylidene difluoride membranes, digested in situ with lysyl endopeptidase, and two radiolabeled peptides isolated by reverse phase-high performance liquid chromatography. These contained an identity of 7/11 with amino acids 119-129, and 11/11 with amino acids 67-77 of human liver glyceraldehyde-3-phosphate dehydrogenase (GAPDH), respectively. Photoaffinity labeling with PNBG-[125I]ASA was blocked completely by 100 microM ATP and greater than 50% with 100 microM NAD+. LTC4-[125I]ASA binding to the NAD+ site was confirmed by V8 protease digestion of purified GAPDH labeled with LTC4-[125I]ASA or PNBG-[125I]ASA, with both labels localized to the 6.8-kDa N-terminal fragment. Photoaffinity labeling of HL-60 cells with LTC4-125I-ASA identified GAPDH as the predominant cytoplasmic binding protein in these cells. These data indicate that GAPDH is a membrane-associated and cytoplasmic protein which binds glutathione conjugates including LTC4.

Adenosine Triphosphate↗
PubMed1995

Ubiquitin fusion proteins are overexpressed in colon cancer but not in gastric cancer.

A cDNA clone (AF3) encoding the ubiquitin A gene 52 amino acid extension fusion protein (UbA52) was isolated from a subtracted cDNA library of human colorectal carcinoma minus adjacent normal mucosa. In Northern hybridization the mRNA signal for UbA52 was greater in surgical samples of colonic carcinoma (T) than in paired adjacent normal (N) tissues in 24 of 29 cases (T/N = 3.4 +/- 0.5, P < 0.01). An oligonucleotide probe specific for only the 52 amino acid extension confirmed the overexpression of UbA52. In contrast, there was no overexpression of UbA52 mRNA in gastric cancer samples (n = 7, T/N = 1.0 +/- 0.3). The mRNA of several ribosomal proteins, and of another ubiquitin A gene fusion protein, UbA80, with an 80 amino acid extension of ribosomal protein S27a, have been reported to be over-expressed in colon cancer, but not as yet at the protein level. Using rabbit antisera to the ribosomal protein component S27a we demonstrate over-expression of S27a at the protein level in colonic (n = 5), but not gastric (n = 6) carcinomas. Therefore it is likely that both UbA80 and UbA52 are overexpressed in colon cancer, but not in gastric cancer.

Base Sequence↗
PubMed1994

Human ribosomal protein L37 has motifs predicting serine/threonine phosphorylation and a zinc-finger domain.

Ribosomal protein L37 mRNA is overexpressed in colon cancer. The nucleotide sequences of human L37 from several tumor and normal, colon and liver cDNA sources were determined to be identical. L37 mRNA was approximately 375 nucleotides long encoding 97 amino acids with M(r) = 11,070, pI = 12.6, multiple potential serine/threonine phosphorylation sites and a zinc-finger domain. The human sequence is compared to other species.

Amino Acid Sequence↗
PubMed1993

Nucleotide and deduced amino acid sequence of human ribosomal protein L18.

Ribosomal protein L18 mRNA is overexpressed in human colorectal cancer compared to normal colon tissue. We report the nucleotide sequence of human L18 cDNA derived from a normal colon source. There were no mutational changes in segments of L18 cDNA derived from two tumor sources. The L18 cDNA was 690 base pairs long and predicts a single open reading frame of 564 nucleotides, encoding 188 amino acids with a M(r) = 21,621, it is homologous to rat L18 and Xenopus laevis L14.

Amino Acid Sequence↗
PubMed1993

Gastric and hepatocellular carcinomas do not overexpress the same ribosomal protein messenger RNAs as colonic carcinoma.

The levels of a number of ribosomal protein mRNAs are reported to be increased in human colon cancer. We have assessed whether selected ribosomal protein mRNAs are overexpressed in other gastrointestinal malignancies, namely gastric and hepatocellular carcinomas. Subtracted complementary DNA libraries were generated from paired samples of human (a) colorectal carcinoma minus adjacent normal colonic mucosa and (b) hepatocellular carcinoma minus adjacent normal liver. Screening of approximately 3% of these library clones determined that ribosomal protein mRNAs encoding L18 and L37 (not previously reported) and P0 and S6 were overexpressed in one or the other library. Their complementary DNA inserts were then used as probes to evaluate their expression in a larger number of paired tumor/normal surgical samples of human colonic, gastric, and hepatocellular carcinomas, by Northern hybridization. The mRNA signal was greater in the colonic carcinoma than in paired adjacent normal colonic mucosa in 38 of 42 cases for P0 [tumor/normal (T/N) ratio = 3.0 +/- 0.3, mean +/- SE, P < 0.001] (G. F. Barnard, R. J. Staniunas, S. Bao, K. Mafune, J. L. Gollan, G. D. Steele, Jr., and L. B. Chen, Cancer Res., 52: 3067-3072, 1992), in 25 of 28 cases for L18 (T/N ratio = 3.7 +/- 0.5, P < 0.001), in 27 of 28 cases for L37 (T/N ratio = 5.3 +/- 0.4, P < 0.001), and in 24 of 28 cases for S6 (T/N ratio = 3.1 +/- 0.5, P < 0.01). The level of mRNA overexpression of L18 and S6 did not correlate with the Dukes' stage of disease. In hepatocellular carcinoma samples, using the same four ribosomal protein complementary DNA probes, only P0 mRNA was significantly increased (T/N ratio = 2.8 +/- 0.4, n = 6, P = 0.047). In gastric carcinoma samples, none of these mRNAs was increased (mean T/N ratios = 0.9-1.2, n = 6). Therefore, gastric and hepatocellular carcinomas do not overexpress the same ribosomal protein mRNAs as do colonic carcinoma.

Base Sequence↗
PubMed1985

The effect of delta 1tetrahydrocannabinol on luteinizing hormone release in castrated and hypothalamic deafferented male rats.

delta 1Tetrahydrocannabinol (THC) acutely suppresses tonic serum luteinizing hormone (LH) and prolactin levels in adult male rats. The exact site of its action has not been identified. We have performed complete hypothalamic deafferentation (CHD), which disrupts the medial basal hypothalamus (MBH) from the rest of the CNS, but did not abolish the ability of THC to suppress hypothalamic-pituitary responses in gonadectomized male rats. This was shown by the equal reduction in serum levels of LH and prolactin in non-deafferented (ND) and CHD animals. These results indicate that THC is able to act inside the MBH and that the MBH-pituitary axis remains responsive to its inhibitory effect despite interruption of the neural connections between the MBH and extrahypothalamic areas. However, the corticotropin releasing factor neurons in the MBH appear functionally impaired as a result of the transection and become unresponsive to the normally produced THC stimulation. Different patterns of action seem to govern the various hypophyseal hormones controlled by the hypothalamus, suggesting that the release of LH releasing hormone and prolactin inhibiting factor might be maintained by the activity of neurons surviving inside the island.

Afferent Pathways↗
PubMed1982

Corticotrophin and corticosterone secretion following delta 1-Tetrahydrocannabinol, in intact and in hypothalamic deafferentated male rats.

Adult male rats, either intact (N) or bearing complete hypothalamic deafferentations (CHD), were injected with delta 1-tetrahydrocannabinol (THC: 5 mg/kg BW, IP). Forty-five minutes later, they were decapitated and trunk blood was collected for serum ACTH and corticosterone (CS) determinations. In the N animals, serum levels of both ACTH and CS were markedly elevated in the drug-treated, as compared to the vehicle-treated group (approximately 8-fold and 10-fold, respectively). In CHD rats, on the contrary, THC administration did not significantly alter serum concentrations of either ACTH or CS. These results demonstrate (1) that acute treatment with THC stimulates the secretion of ACTH as well as of CS; and (2) that extrahypothalamic sites and/or neural pathways mediate this effect.

Adrenocorticotropic Hormone↗
PubMed1978

Changes in rodent thyroid hormones and cyclic-AMP following treatment with pineal indolic compounds.

Treatment of rats with pineal indolic compounds 5-methoxytryptophol, 5-hydroxytryptophol and serotonin brought about a significant increase in serum thyroxine levels, while serotonin and melatonin caused an increase in thyroid cAMP content with corresponding decrease in the gland's hormones. The total quantity of cAMP in the thyroid was also increased by melatonin in the organ culture system. All these findings would indicate that some of the pineal indoleamines elicit a direct action on the thyroid by stimulating the adenyl cyclase activity and intrathyroidal cAMP, bringing about increased release of thyroxine into the blood stream, and that this is usually not accompanied by adequate synthesis in the gland. Our observation that continuous darkness, which stimulates pineal activity, also brought about an increase in cAMP, concours with our finding of a stimulatory effect of the indolic compounds on thyroid hormone release.

Animals↗
PubMed1977

Acute effect of delta1-tetrahydrocannabinol on the hypothalamo-pituitary-ovarian axis in the rat.

Administration of delta1-tetrahydrocannabinol (delta1-THC), the principal psychoactive ingredient of cannabis, to proestrous rats (2 mg/rat, i.p., between 12.00 and 16.00 h) suppressed the proestrous rise in the plasma levels of LH, FSH and prolactin (Prl) and caused a 24 h delay in ovulation. Furthermore, the increased accumulation of prostaglandins of the E-type (PGE) in the ovaries, normally seen on the evening of proestrus, was prevented. Earlier (08.00-10.30 h) or later (18.00 h) administration of the drug on the day of proestrus was only partially effective in inhibiting ovulation. The suppressive effects of delta1-THC on ovulation and gonadotropin secretion were prevented by administration of gonadetropin releasing hormone (GnRH, 0.2 microgram/rat) 1 h after the drug, indicating that the central action of delta1-THC was exerted on the hypothalamus and not on the pituitary gland. Administration of ovine luteinizing hormore (oLH, 2.5 microgram/rat at 16.30 h on the day of proestrus restored ovulation and ovarian PGE accumulation in Nembutal-treated rats, but not in delta1-THC-treated rats; higher doses of oLH (5-10 microgram/rat) reversed the action of delta1-THC on these two parameters.

Animals↗