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At least 19 recordsLinked to original sources
PubMed2025

A novel regulation on the developmental checkpoint protein Sda that controls sporulation and biofilm formation in Bacillus subtilis.

UNLABELLED: Biofilm formation by Bacillus subtilis is triggered by an unusually simple environmental sensing mechanism. Certain serine codons, the four TCN codons (N for A, T, C, or G), in the gene for the biofilm repressor SinR caused lowered SinR translation and subsequent biofilm induction during transition from exponential to stationary growth. Global ribosome profiling showed that ribosomes pause when translating the four UCN (U for T on the mRNA) serine codons on mRNA, but not the two AGC/AGU serine codons. We proposed a serine codon hierarchy (AGC/AGT vs TCN) in that genes enriched in the TCN serine codons may experience reduced translation efficiency when serine is limited. In this study, we designed an algorithm to score all protein-coding genes in B. subtilis NCIB3610 based on the serine codon hierarchy. We generated a short list of 50 genes that could be subject to regulation by this novel mechanism. We further investigated one such gene from the list, sda, which encodes a developmental checkpoint protein regulating both sporulation and biofilm formation. We showed that synonymously switching the TCN serine codons to AGC in sda led to delayed biofilm formation and sporulation. This engineered strain also outgrew strains with other synonymously substituted sda alleles (TCN) in competition assays for biofilm formation and sporulation. Finally, we showed that the AGC serine codon substitutions in sda elevated the Sda protein levels. This serine codon hierarchy-based novel signaling mechanism could be exploited by bacteria in adapting to stationary phase and regulating important biological processes. IMPORTANCE: Genome-wide ribosome profiling in Bacillus subtilis shows that under serine limitation, ribosomes pause on the four TCN (N for A, C, G, and T), but not AGC/AGT serine codons, during translation at a global scale. This serine codon hierarchy (AGC/T vs TCN) differentially influences the translation efficiency of genes enriched in certain serine codons. In this study, we designed an algorithm to score all 4,000+ genes in the B. subtilis genome and generated a list of 50 genes that could be subject to this novel serine codon hierarchy-mediated regulation. We further investigated one such gene, sda, encoding a developmental checkpoint protein. We show that sda and cell developments controlled by Sda are also regulated by this novel mechanism.

Bacillus subtilis↗
PubMed1988

The Sda antigen in the human kidney and colon.

The range of concentration of the Sda blood group antigen has been determined in the human adult kidney and colon. No Sda antigen was found in 2% of kidneys. Immunofluorescent studies of the kidney showed that Sda is present in the distal convoluted tubules and collecting ducts and occurs in the same location as Tamm-Horsfall protein. No Sda antigen was detected in about 2% of colons. In an additional 6%, no antigen was detected in saline extracts but was present in an insoluble form. In the colon, Sda is sited on the brush borders of the epithelial cells and in the goblet cells. No Tamm-Horsfall protein was identified in the colon.

Adult↗
PubMed1992

A hemolytic reaction implicating Sda antibody missed by immediate spin crossmatch.

Anti-Sda, an antibody not usually considered to cause of hemolytic transfusion reactions, possibly was related to hemolysis following transfusion of red blood cells expressing strong Sda antigen. Prior to transfusion, the antiglobulin antibody screen performed in LISS and an immediate spin crossmatch were negative. Retrospectively, after hemolysis was detected, an antiglobulin crossmatch with red cells from the transfused unit revealed microscopic incompatibility. The transfused unit proved to have strong expression of Sda antigen-facilitating identification of a weak Sda antibody in our patient. In addition, this case represents an unusual instance in which an antibody screen plus an immediate spin crossmatch failed to detect an incompatibility that would have been apparent had an antiglobulin crossmatch been performed.

Blood Grouping and Crossmatching↗
PubMed1988

Monoclonal antibodies specific for T cell-associated carbohydrate determinants react with human blood group antigens CAD and SDA.

The CT antigenic determinants have previously been shown to be present on the T200 glycoproteins and other proteins of murine cytotoxic T cell clones but not of T helper clones or nonactivated lymphocytes (1, 2). Two determinants recognized by mAbs CT1 and CT2 are also expressed on thymocytes in a developmentally regulated fashion during fetal thymus ontogeny and are found in a subset of Lyt-2+ intraepithelial lymphocytes in the intestinal mucosa (3-5). Previous studies of the biosynthesis of CT+ proteins suggested that these determinants were composed of carbohydrate (8). We now demonstrate that the anti-CT mAbs react with a carbohydrate determinant at the nonreducing terminus of O-linked oligosaccharides that has the configuration GalNAc beta 1,4[SA alpha 2,3]-galactose. The CT antibodies detected this determinant not only on CTL clones but also in the human blood group antigens Cad and Sda+. Variant CTL lines, non-Cad erythrocytes, and Sda- glycoproteins that lacked the GalNAc residue did not bind the CT mAb. Sialic acid was essential for CT antigen expression since neuraminidase or mild periodate treatment abrogated CT antibody binding. In addition, other carbohydrate structures with terminal GalNAc residues such as the A or Tn blood group antigens were not recognized. The CT antibodies thus define GalNAc and sialic acid containing carbohydrate antigens that are expressed on discrete subsets of T lymphocytes and may also be useful reagents for the detection of Cad and Sda+ blood group antigens.

Animals↗
PubMed1990

Postnatal development of rat colon epithelial cells is associated with changes in the expression of the beta 1,4-N-acetylgalactosaminyltransferase involved in the synthesis of Sda antigen of alpha 2,6-sialyltransferase activity towards N-acetyl-lactosamine.

beta 1,4-N-Acetylgalactosaminyltransferase (beta 1,4GalNAc-transferase) and alpha 2,3-sialyltransferase are both involved in the biosynthesis of the Sda blood group antigen, which is also present in cells of large intestine. The expression of these enzymes and of alpha 2,6-sialyltransferase activity towards N-acetyl-lactosamine was investigated in rat intestinal cells and correlated with both cell differentiation and extent of postnatal maturation. The beta 1,4GalNAc-transferase activity was exclusively found in epithelial cells of the large intestine, preferentially in the proximal segments suggesting a proximal-distal gradient of expression. The beta 1,4GalNAc-transferase and alpha 2,3-sialyltransferase activity towards N-acetyl-lactosamine were expressed in all cell fractions of the colonic crypt, with a maximum activity in the deeply located cells; therefore Sda antigen biosynthesis appears to occur preferentially at a specific stage of cell differentiation. By using N-acetyl-lactosamine as an acceptor, the predominant sialyltransferase in the colon cells was that capable of adding sialic acid in the alpha 2,3- linkage, whereas in the ileum cells the major enzyme was that forming the alpha 2,6-isomer. There were dramatic changes in the expression of colonic beta 1,4GalNac-transferase and of alpha 2,6-sialyltransferase activity towards N-acetyl-lactosamine during postnatal maturation. The former enzyme, practically absent at birth, increased slowly in the first days of life and then rapidly after weaning; by contrast, the latter enzyme was largely expressed only in newborn animals. As the colonic alpha 2,3-sialyltransferase activity towards N-acetyl-lactosamine did not change during the postnatal period, the ratio between the alpha 2,6- and alpha 2,3-sialyltransferase activities was reversed after weaning.

Amino Sugars↗
PubMed1976

Cad(super Sda) in a British family with eastern connections: a note on the specificity of the Dolichos biflorus lectin.

Cad, Sd(a++) or Super Sda is a rare, inherited, dominant blood group character which is of much interest, not only with regard to problems in pretransfusion tests (erythrocyte polyagglutination) but also in the field of lectin specificity. We have studied this blood group character in a British family with Eastern connections and present a brief account of its serological and clinical importance. Most persons are Sd(a+) but there is a wide distribution of antigen strength, ranging from ordinary Sd(a+) to Cad. Most persons also have weak anti-Sda in their serum; this is ordinarily of no clinical importance, but could cause problems if Cad bloods are transfused. The chief structural determinant of Cad specificity is N-acetyl-D-galactosamine in alpha-linked position, yet it is clearly distinguishable by use of appropriate lectins from other blood group antigens, A and Tn, which also have this acetyl-hexosamine as their chief structural determinant. A method for the rapid identification of Cad, applicable to all ABO groups, is described. The lectin of Dolichos biflorus, which is specific for N-acetyl-D-galactosamine in alpha-linked position, reacts strongly with A(A1), Tn and Cad cells, its action on Cad cells being much the strongest. Absorption-elution studies show that one and the same lectin reacts with both A1 and Tn cells. Absorption with Cad cells abolishes activity for A1, Tn and Cad cells; whereas absorption with A1 or Tn cells leaves activity for Cad. This does not necessarily indicate that anti-Cad is a separate component since the same result can be obtained by simply diluting the Dolichos reagent. However, eluates from Cad cells react only with Cad cells, whereas eluates from A1 or Tn cells react with A1, Tn and Cad cells.

ABO Blood-Group System↗
PubMed1991

Detection of serum antibodies using LBC cell-grown sialodacryoadenitis (SDA) virus.

The TG strain of sialodacryoadenitis (SDA) virus propagated in LBC cell culture (TGr/LBC) reacted strongly with anti-TGr rat serum in complement fixation (CF) tests, showing much higher titers with anti-TGr rat serum than mouse hepatitis virus MHV-NuU antigen. The antigenicity was not affected after ether treatment while infectivity was lost. The TGr/LBC antigen might be useful in seromonitoring for SDA infection in rats.

Animals↗
PubMed1989

Enzymic synthesis, chemical characterisation and Sda activity of GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4GlcNAc and GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4Glc.

The tetrasaccharides GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4Glc and GalNAc beta 1-4[NeuAc alpha 2-3]Gal beta 1-4GlcNAc were synthesised by enzymic transfer of GalNAc from UDP-GalNAc to 3'-sialyllactose (NeuAc alpha 2-3 Gal beta 1-4Glc) and 3'-sialyl-N-acetyllactosamine (NeuAc alpha 2-3Gal beta 1-4GlcNAc). The structures of the products were established by methylation and 1H-500 MHz NMR spectroscopy. In Sda serological tests the product formed with 3'-sialyl-N-acetyllactosamine was highly active whereas that formed with 3'-sialyllactose had only weak activity.

Animals↗
PubMed1991

UDP-GalNAc:NeuAc alpha 2,3Gal beta-R (GalNAc to Gal) beta 1,4-N-acetylgalactosaminyltransferase responsible for the Sda specificity in human colon carcinoma CaCo-2 cell line.

The UDP-GalNAc:NeuAc alpha 2,3Gal beta-R (GalNAc to Gal) beta-1,4-N-acetylgalactosaminyltransferase (beta 1,4GalNAc-transferase) is the enzyme responsible for the addition of the immunodominant sugar of the Sda isto-blood group determinant. In humans the enzyme is mainly expressed in the large intestine. We screened nine human colorectal carcinoma cell lines (SW-948, SW-948 FL, SW-480, SW-48, SW-1417, COLO-205, LOVO, HT-29 and CaCo-2) in order to ascertain the occurrence of beta 1,4GalNAc-transferase. Only in CaCo-2 cells the glycosyltransferase was detected and the activity increased with the degree of enterocytic differentiation. Nevertheless, in highly differentiated CaCo-2 cells the activity was thirty times lower than that found in cells detached from normal colon mucosa. These results support the notion that the expression of beta 1,4GalNAc-transferase is a marker of the colonic cell maturation.

Blood Group Antigens↗
PubMed1986

Characterization of N-acetyl-beta-D-galactosaminyltransferase from guinea-pig kidney involved in the biosynthesis of Sda antigen associated with Tamm-Horsfall glycoprotein.

This study reports the catalytic activity of N-acetyl-beta-D-galactosaminyltransferase from guinea-pig kidney towards such non-glycoprotein acceptors as small oligosaccharides and glycolipids, having a carbohydrate structure similar to that of the Sda antigen associated with human Tamm-Horsfall glycoprotein. 3'-O-Sialyllactose, but not 6'-O-sialyllactose or lactose, was an effective acceptor of the glycosyltransferase. On the basis of enzymic and chemical treatment of the tetrasaccharide obtained by the transfer of [14C]GalNAc to 3'-O-sialyllactose, we propose that the glycosyltransferase attaches beta-D-GalNAc to O-4 of the galactose residue that is substituted at O-3 by sialic acid. The GM3 ganglioside, in which the identical carbohydrate moiety of 3'-O-sialyllactose is bound to a ceramide residue, did not serve as an acceptor of the kidney-N-acetyl-beta-D-galactosaminyltransferase and did not behave as a competitive inhibitor of the Tamm-Horsfall glycoprotein in the transferase assay. These results indicate that the hydrophobic moiety in the ganglioside hinders the action of N-acetylgalactosaminyltransferase. Study of the transferase activity towards a heterogeneous glycopeptide species prepared from a Sd(a-) Tamm-Horsfall glycoprotein indicated that guinea-pig kidney enzyme preferentially transferred [14C]GalNAc to the oligosaccharides having a tetraantennary branching-structure.

Animals↗
PubMed1989

Expression of UDP-GalNAc:NeuAc alpha 2,3Gal beta-R beta 1,4(GalNAc to Gal) N-acetylgalactosaminyltransferase involved in the synthesis of Sda antigen in human large intestine and colorectal carcinomas.

N-Acetylgalactosamine beta 1,4-linked to a galactose residue substituted in O-3 with one N-acetylneuraminic acid residue is the immunodominant sugar of the human blood group Sda antigen which is also largely present in the kidney medulla and colon mucosa. A beta 1,4-N-acetylgalactosaminyltransferase very similar to that previously described in urine of Sd(a+) individuals (F. Serafini-Cessi, N. Malagolini, and F. Dall'Olio. Arch. Biochem. Biophys., 266: 573-582, 1988) has been identified in cells released from human large intestine. The higher values of beta 1,4-N-acetylgalactosaminyltransferase activity were detected in proximal and medial segments of the large intestine, suggesting a proximal-distal gradient of the enzyme expression. When the beta 1,4-N-acetylgalactosaminyltranferase activity of colorectal carcinoma specimens from 18 patients was compared with that of the normal mucosa surrounding the tumor, a constant and in several cases drastic reduction of the activity was detected in tumor cells. Three human colorectal adenocarcinoma cell lines (Colo-205, SW-48, and SW-948) have been found to lack the beta 1,4-N-acetylgalactosaminyltransferase activity. Altogether, these results support the notion that the malignant transformation drastically affects the expression of this glycosyltransferase in large bowel cells.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1978

Relation of specific dynamic action of food (SDA) to growth in rats.

The relation between food induced thermogenesis and anabolic processes was investigated in normal and malnourished rats. The metabolic rate was measured 5 and 17 hr after food removal. The difference between the two measurements was 3.9% during growth arrest of malnourished rats gaining 0.6 g/day, but 20.0 and 28.7% during growth recovery when rats were gaining 4.1 and 5.3 g/day, respectively. The 5 hr postprandial metabolic rates rose in normal rats from 15.6 kcal/day at 4 weeks to 45.3 kcal/day at 15 weeks, and then declined to 38.5 kcal/day at 36 weeks. The difference between 5 and 17 hr postprandial metabolic rates was 28.8% in 5 to 15-week-old rats gaining 5.2 g/day, and 1.1% in 24 to 32-week-old rats who were no longer gaining weight.

Aging↗