The identification of a novel human integrin $/beta$ subunit, $/beta/sb7$, has been reported in this dissertation. The full-length human $/beta/sb7$ cDNA contains 2798 nucleotides encoding a single long open reading frame of 798 amino acid residues of which 708 are extracellular and 52 are cytoplasmic. The human $/beta/sb7$ sequence displays strong homology with other integrin $/beta$ subunits, being most related to $/beta/sb2$. Cell distribution studies suggest that the expression of transcripts encoding the human $/beta/sb7$ subunit is restricted to leukocytes. This study was the first to show that the cysteine-rich repeats of the human integrin $/beta/sb7$ subunit and other integrin $/beta$ subunits are related to domain III of the laminin B chains. Furthermore, the integrin $/beta$ subunit and laminin cysteine-rich repeats are each related to the epidermal growth factor (EGF)-like repeats found in a growing number of adhesion molecules and regulatory proteins. The mouse homologue of the human $/beta/sb7$ subunit has also been cloned in this study, and it shares 87% amino acid identity with the human $/beta/sb7$ sequence. The mouse $/beta/sb7$ mRNA transcripts, like that of the human $/beta/sb7$, have a predominantly leukocyte-restricted expression, but in some haematopoietic lineage cell lines, in addition to the predominant 3 kb transcript, a less abundant 2 kb transcript is also detectable. Cultured mouse skin epithelial cells contain only the 2 kb transcript. The genes encoding the human and mouse $/beta/sb7$ subunits were mapped to human chromosome 12 (ITGB7) and mouse chromosome 15 (Itgb-7). The Itgb-7 gene was localised to the distal part of mouse chromosome 15, and exists in the gene order: Myc-Wnt-1-Itgb-1. The N-terminal 13 amino acids of the mature mouse $/beta/sb7$ subunit was shown to be identical to a 13 amino acid N-terminal sequence reported for the Mr 120,000 $/beta$ subunit of the M290 antigen, which is found highly expressed on mouse intestinal intraepithelial lymphocytes (IEL). This finding suggests that the integrin $/beta/sb7$ subunit may play important roles in IEL migration, and immunosurveillance in the gut mucosa. / Subscription resource available via Digital Dissertations only.

Human galectin-1 is a soluble form of lectin known to play a role in various cellular processes by mediating recognition events in which glycoconjugates are implicated. As a number of studies have shown that galectin-1 is a growth inhibitor (Wells and Mallucci, 1991; Manilal et al., 1993), the starting hypothesis for this thesis was that galectin-1 might be a substrate for a growth-related proteinase (GRP). The intention was to identify the mechanism of action responsible for this growth-inhibitory property by looking at the effect of galectin treatment on the expression of the c-fos proto-oncogene. The structure of the recombinant galectin-1 molecule was investigated in mass spectrometry determinations. Galectin-1 was further characterised in hemagglutination, cellular growth, cytotoxicity, proteolysis and cellular degradation experiments. Even though the recombinant galectin-1 was not identical with the natural protein because it contained two pGEX-linker amino acid residues, and had an apparently 933 Da bigger molecular weight, it fully retained the carbohydrate binding and mitogenicity properties and was still a biphasic growth modulator. Repeated DNA sequencing and mass spectrometry determinations of the tryptic peptides have accounted for all the galectin molecule and have not detected an insertion. We concluded that the abnormal size was the result of a calibration error in the mass spectrometer. Even though the recombinant galectin was proved to be very susceptible to soluble proteinase action, there was no evidence for its active degradation when incubated with cells, and this disproved the original hypothesis. We showed for the first time that $/alpha/sb1$-antitrypsin inhibitor (which inhibits the GRP) had a down-regulatory effect on c-fos expression. Galectin-1 treatment of U2OS and HELA cells had a downregulatory effect on c-fos expression, which confirmed the hypothesis that this proto-oncogene is affected by the signal transduction pathway through which galectin-1 inhibits cell growth. C-fos expression is affected in HELA cells even though they do not undergo growth inhibition, indicating that this process is not as simple as we initially believed. Galectin-1 treatment also downregulated galectin-1 gene expression. This meant that feedback inhibition could take place in these tumour cells. / Subscription resource available via Digital Dissertations only.

The identification of a novel human integrin $/beta$ subunit, $/beta/sb7$, has been reported in this dissertation. The full-length human $/beta/sb7$ cDNA contains 2798 nucleotides encoding a single long open reading frame of 798 amino acid residues of which 708 are extracellular and 52 are cytoplasmic. The human $/beta/sb7$ sequence displays strong homology with other integrin $/beta$ subunits, being most related to $/beta/sb2$. Cell distribution studies suggest that the expression of transcripts encoding the human $/beta/sb7$ subunit is restricted to leukocytes. This study was the first to show that the cysteine-rich repeats of the human integrin $/beta/sb7$ subunit and other integrin $/beta$ subunits are related to domain III of the laminin B chains. Furthermore, the integrin $/beta$ subunit and laminin cysteine-rich repeats are each related to the epidermal growth factor (EGF)-like repeats found in a growing number of adhesion molecules and regulatory proteins. The mouse homologue of the human $/beta/sb7$ subunit has also been cloned in this study, and it shares 87% amino acid identity with the human $/beta/sb7$ sequence. The mouse $/beta/sb7$ mRNA transcripts, like that of the human $/beta/sb7$, have a predominantly leukocyte-restricted expression, but in some haematopoietic lineage cell lines, in addition to the predominant 3 kb transcript, a less abundant 2 kb transcript is also detectable. Cultured mouse skin epithelial cells contain only the 2 kb transcript. The genes encoding the human and mouse $/beta/sb7$ subunits were mapped to human chromosome 12 (ITGB7) and mouse chromosome 15 (Itgb-7). The Itgb-7 gene was localised to the distal part of mouse chromosome 15, and exists in the gene order: Myc-Wnt-1-Itgb-1. The N-terminal 13 amino acids of the mature mouse $/beta/sb7$ subunit was shown to be identical to a 13 amino acid N-terminal sequence reported for the Mr 120,000 $/beta$ subunit of the M290 antigen, which is found highly expressed on mouse intestinal intraepithelial lymphocytes (IEL). This finding suggests that the integrin $/beta/sb7$ subunit may play important roles in IEL migration, and immunosurveillance in the gut mucosa. / Subscription resource available via Digital Dissertations only.

Human galectin-1 is a soluble form of lectin known to play a role in various cellular processes by mediating recognition events in which glycoconjugates are implicated. As a number of studies have shown that galectin-1 is a growth inhibitor (Wells and Mallucci, 1991; Manilal et al., 1993), the starting hypothesis for this thesis was that galectin-1 might be a substrate for a growth-related proteinase (GRP). The intention was to identify the mechanism of action responsible for this growth-inhibitory property by looking at the effect of galectin treatment on the expression of the c-fos proto-oncogene. The structure of the recombinant galectin-1 molecule was investigated in mass spectrometry determinations. Galectin-1 was further characterised in hemagglutination, cellular growth, cytotoxicity, proteolysis and cellular degradation experiments. Even though the recombinant galectin-1 was not identical with the natural protein because it contained two pGEX-linker amino acid residues, and had an apparently 933 Da bigger molecular weight, it fully retained the carbohydrate binding and mitogenicity properties and was still a biphasic growth modulator. Repeated DNA sequencing and mass spectrometry determinations of the tryptic peptides have accounted for all the galectin molecule and have not detected an insertion. We concluded that the abnormal size was the result of a calibration error in the mass spectrometer. Even though the recombinant galectin was proved to be very susceptible to soluble proteinase action, there was no evidence for its active degradation when incubated with cells, and this disproved the original hypothesis. We showed for the first time that $/alpha/sb1$-antitrypsin inhibitor (which inhibits the GRP) had a down-regulatory effect on c-fos expression. Galectin-1 treatment of U2OS and HELA cells had a downregulatory effect on c-fos expression, which confirmed the hypothesis that this proto-oncogene is affected by the signal transduction pathway through which galectin-1 inhibits cell growth. C-fos expression is affected in HELA cells even though they do not undergo growth inhibition, indicating that this process is not as simple as we initially believed. Galectin-1 treatment also downregulated galectin-1 gene expression. This meant that feedback inhibition could take place in these tumour cells. / Subscription resource available via Digital Dissertations only.

The identification of a novel human integrin $/beta$ subunit, $/beta/sb7$, has been reported in this dissertation. The full-length human $/beta/sb7$ cDNA contains 2798 nucleotides encoding a single long open reading frame of 798 amino acid residues of which 708 are extracellular and 52 are cytoplasmic. The human $/beta/sb7$ sequence displays strong homology with other integrin $/beta$ subunits, being most related to $/beta/sb2$. Cell distribution studies suggest that the expression of transcripts encoding the human $/beta/sb7$ subunit is restricted to leukocytes. This study was the first to show that the cysteine-rich repeats of the human integrin $/beta/sb7$ subunit and other integrin $/beta$ subunits are related to domain III of the laminin B chains. Furthermore, the integrin $/beta$ subunit and laminin cysteine-rich repeats are each related to the epidermal growth factor (EGF)-like repeats found in a growing number of adhesion molecules and regulatory proteins. The mouse homologue of the human $/beta/sb7$ subunit has also been cloned in this study, and it shares 87% amino acid identity with the human $/beta/sb7$ sequence. The mouse $/beta/sb7$ mRNA transcripts, like that of the human $/beta/sb7$, have a predominantly leukocyte-restricted expression, but in some haematopoietic lineage cell lines, in addition to the predominant 3 kb transcript, a less abundant 2 kb transcript is also detectable. Cultured mouse skin epithelial cells contain only the 2 kb transcript. The genes encoding the human and mouse $/beta/sb7$ subunits were mapped to human chromosome 12 (ITGB7) and mouse chromosome 15 (Itgb-7). The Itgb-7 gene was localised to the distal part of mouse chromosome 15, and exists in the gene order: Myc-Wnt-1-Itgb-1. The N-terminal 13 amino acids of the mature mouse $/beta/sb7$ subunit was shown to be identical to a 13 amino acid N-terminal sequence reported for the Mr 120,000 $/beta$ subunit of the M290 antigen, which is found highly expressed on mouse intestinal intraepithelial lymphocytes (IEL). This finding suggests that the integrin $/beta/sb7$ subunit may play important roles in IEL migration, and immunosurveillance in the gut mucosa. / Subscription resource available via Digital Dissertations only.

Human galectin-1 is a soluble form of lectin known to play a role in various cellular processes by mediating recognition events in which glycoconjugates are implicated. As a number of studies have shown that galectin-1 is a growth inhibitor (Wells and Mallucci, 1991; Manilal et al., 1993), the starting hypothesis for this thesis was that galectin-1 might be a substrate for a growth-related proteinase (GRP). The intention was to identify the mechanism of action responsible for this growth-inhibitory property by looking at the effect of galectin treatment on the expression of the c-fos proto-oncogene. The structure of the recombinant galectin-1 molecule was investigated in mass spectrometry determinations. Galectin-1 was further characterised in hemagglutination, cellular growth, cytotoxicity, proteolysis and cellular degradation experiments. Even though the recombinant galectin-1 was not identical with the natural protein because it contained two pGEX-linker amino acid residues, and had an apparently 933 Da bigger molecular weight, it fully retained the carbohydrate binding and mitogenicity properties and was still a biphasic growth modulator. Repeated DNA sequencing and mass spectrometry determinations of the tryptic peptides have accounted for all the galectin molecule and have not detected an insertion. We concluded that the abnormal size was the result of a calibration error in the mass spectrometer. Even though the recombinant galectin was proved to be very susceptible to soluble proteinase action, there was no evidence for its active degradation when incubated with cells, and this disproved the original hypothesis. We showed for the first time that $/alpha/sb1$-antitrypsin inhibitor (which inhibits the GRP) had a down-regulatory effect on c-fos expression. Galectin-1 treatment of U2OS and HELA cells had a downregulatory effect on c-fos expression, which confirmed the hypothesis that this proto-oncogene is affected by the signal transduction pathway through which galectin-1 inhibits cell growth. C-fos expression is affected in HELA cells even though they do not undergo growth inhibition, indicating that this process is not as simple as we initially believed. Galectin-1 treatment also downregulated galectin-1 gene expression. This meant that feedback inhibition could take place in these tumour cells. / Subscription resource available via Digital Dissertations only.

The identification of a novel human integrin $/beta$ subunit, $/beta/sb7$, has been reported in this dissertation. The full-length human $/beta/sb7$ cDNA contains 2798 nucleotides encoding a single long open reading frame of 798 amino acid residues of which 708 are extracellular and 52 are cytoplasmic. The human $/beta/sb7$ sequence displays strong homology with other integrin $/beta$ subunits, being most related to $/beta/sb2$. Cell distribution studies suggest that the expression of transcripts encoding the human $/beta/sb7$ subunit is restricted to leukocytes. This study was the first to show that the cysteine-rich repeats of the human integrin $/beta/sb7$ subunit and other integrin $/beta$ subunits are related to domain III of the laminin B chains. Furthermore, the integrin $/beta$ subunit and laminin cysteine-rich repeats are each related to the epidermal growth factor (EGF)-like repeats found in a growing number of adhesion molecules and regulatory proteins. The mouse homologue of the human $/beta/sb7$ subunit has also been cloned in this study, and it shares 87% amino acid identity with the human $/beta/sb7$ sequence. The mouse $/beta/sb7$ mRNA transcripts, like that of the human $/beta/sb7$, have a predominantly leukocyte-restricted expression, but in some haematopoietic lineage cell lines, in addition to the predominant 3 kb transcript, a less abundant 2 kb transcript is also detectable. Cultured mouse skin epithelial cells contain only the 2 kb transcript. The genes encoding the human and mouse $/beta/sb7$ subunits were mapped to human chromosome 12 (ITGB7) and mouse chromosome 15 (Itgb-7). The Itgb-7 gene was localised to the distal part of mouse chromosome 15, and exists in the gene order: Myc-Wnt-1-Itgb-1. The N-terminal 13 amino acids of the mature mouse $/beta/sb7$ subunit was shown to be identical to a 13 amino acid N-terminal sequence reported for the Mr 120,000 $/beta$ subunit of the M290 antigen, which is found highly expressed on mouse intestinal intraepithelial lymphocytes (IEL). This finding suggests that the integrin $/beta/sb7$ subunit may play important roles in IEL migration, and immunosurveillance in the gut mucosa. / Subscription resource available via Digital Dissertations only.

Human galectin-1 is a soluble form of lectin known to play a role in various cellular processes by mediating recognition events in which glycoconjugates are implicated. As a number of studies have shown that galectin-1 is a growth inhibitor (Wells and Mallucci, 1991; Manilal et al., 1993), the starting hypothesis for this thesis was that galectin-1 might be a substrate for a growth-related proteinase (GRP). The intention was to identify the mechanism of action responsible for this growth-inhibitory property by looking at the effect of galectin treatment on the expression of the c-fos proto-oncogene. The structure of the recombinant galectin-1 molecule was investigated in mass spectrometry determinations. Galectin-1 was further characterised in hemagglutination, cellular growth, cytotoxicity, proteolysis and cellular degradation experiments. Even though the recombinant galectin-1 was not identical with the natural protein because it contained two pGEX-linker amino acid residues, and had an apparently 933 Da bigger molecular weight, it fully retained the carbohydrate binding and mitogenicity properties and was still a biphasic growth modulator. Repeated DNA sequencing and mass spectrometry determinations of the tryptic peptides have accounted for all the galectin molecule and have not detected an insertion. We concluded that the abnormal size was the result of a calibration error in the mass spectrometer. Even though the recombinant galectin was proved to be very susceptible to soluble proteinase action, there was no evidence for its active degradation when incubated with cells, and this disproved the original hypothesis. We showed for the first time that $/alpha/sb1$-antitrypsin inhibitor (which inhibits the GRP) had a down-regulatory effect on c-fos expression. Galectin-1 treatment of U2OS and HELA cells had a downregulatory effect on c-fos expression, which confirmed the hypothesis that this proto-oncogene is affected by the signal transduction pathway through which galectin-1 inhibits cell growth. C-fos expression is affected in HELA cells even though they do not undergo growth inhibition, indicating that this process is not as simple as we initially believed. Galectin-1 treatment also downregulated galectin-1 gene expression. This meant that feedback inhibition could take place in these tumour cells. / Subscription resource available via Digital Dissertations only.

The identification of a novel human integrin $/beta$ subunit, $/beta/sb7$, has been reported in this dissertation. The full-length human $/beta/sb7$ cDNA contains 2798 nucleotides encoding a single long open reading frame of 798 amino acid residues of which 708 are extracellular and 52 are cytoplasmic. The human $/beta/sb7$ sequence displays strong homology with other integrin $/beta$ subunits, being most related to $/beta/sb2$. Cell distribution studies suggest that the expression of transcripts encoding the human $/beta/sb7$ subunit is restricted to leukocytes. This study was the first to show that the cysteine-rich repeats of the human integrin $/beta/sb7$ subunit and other integrin $/beta$ subunits are related to domain III of the laminin B chains. Furthermore, the integrin $/beta$ subunit and laminin cysteine-rich repeats are each related to the epidermal growth factor (EGF)-like repeats found in a growing number of adhesion molecules and regulatory proteins. The mouse homologue of the human $/beta/sb7$ subunit has also been cloned in this study, and it shares 87% amino acid identity with the human $/beta/sb7$ sequence. The mouse $/beta/sb7$ mRNA transcripts, like that of the human $/beta/sb7$, have a predominantly leukocyte-restricted expression, but in some haematopoietic lineage cell lines, in addition to the predominant 3 kb transcript, a less abundant 2 kb transcript is also detectable. Cultured mouse skin epithelial cells contain only the 2 kb transcript. The genes encoding the human and mouse $/beta/sb7$ subunits were mapped to human chromosome 12 (ITGB7) and mouse chromosome 15 (Itgb-7). The Itgb-7 gene was localised to the distal part of mouse chromosome 15, and exists in the gene order: Myc-Wnt-1-Itgb-1. The N-terminal 13 amino acids of the mature mouse $/beta/sb7$ subunit was shown to be identical to a 13 amino acid N-terminal sequence reported for the Mr 120,000 $/beta$ subunit of the M290 antigen, which is found highly expressed on mouse intestinal intraepithelial lymphocytes (IEL). This finding suggests that the integrin $/beta/sb7$ subunit may play important roles in IEL migration, and immunosurveillance in the gut mucosa. / Subscription resource available via Digital Dissertations only.

Human galectin-1 is a soluble form of lectin known to play a role in various cellular processes by mediating recognition events in which glycoconjugates are implicated. As a number of studies have shown that galectin-1 is a growth inhibitor (Wells and Mallucci, 1991; Manilal et al., 1993), the starting hypothesis for this thesis was that galectin-1 might be a substrate for a growth-related proteinase (GRP). The intention was to identify the mechanism of action responsible for this growth-inhibitory property by looking at the effect of galectin treatment on the expression of the c-fos proto-oncogene. The structure of the recombinant galectin-1 molecule was investigated in mass spectrometry determinations. Galectin-1 was further characterised in hemagglutination, cellular growth, cytotoxicity, proteolysis and cellular degradation experiments. Even though the recombinant galectin-1 was not identical with the natural protein because it contained two pGEX-linker amino acid residues, and had an apparently 933 Da bigger molecular weight, it fully retained the carbohydrate binding and mitogenicity properties and was still a biphasic growth modulator. Repeated DNA sequencing and mass spectrometry determinations of the tryptic peptides have accounted for all the galectin molecule and have not detected an insertion. We concluded that the abnormal size was the result of a calibration error in the mass spectrometer. Even though the recombinant galectin was proved to be very susceptible to soluble proteinase action, there was no evidence for its active degradation when incubated with cells, and this disproved the original hypothesis. We showed for the first time that $/alpha/sb1$-antitrypsin inhibitor (which inhibits the GRP) had a down-regulatory effect on c-fos expression. Galectin-1 treatment of U2OS and HELA cells had a downregulatory effect on c-fos expression, which confirmed the hypothesis that this proto-oncogene is affected by the signal transduction pathway through which galectin-1 inhibits cell growth. C-fos expression is affected in HELA cells even though they do not undergo growth inhibition, indicating that this process is not as simple as we initially believed. Galectin-1 treatment also downregulated galectin-1 gene expression. This meant that feedback inhibition could take place in these tumour cells. / Subscription resource available via Digital Dissertations only.