• Journal of Microbiology and Biotechnology
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• v.31 no.7
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• pp.1035-1043
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• 2021

Although engineered Saccharomyces cerevisiae fermenting cellobiose is useful for the production of biofuels from cellulosic biomass, cellodextrin accumulation is one of the main problems reducing ethanol yield and productivity in cellobiose fermentation with S. cerevisiae expressing cellodextrin transporter (CDT) and intracellular β-glucosidase (GH1-1). In this study, we investigated the reason for the cellodextrin accumulation and how to alleviate its formation during cellobiose fermentation using engineered S. cerevisiae fermenting cellobiose. From the series of cellobiose fermentation using S. cerevisiae expressing only GH1-1 under several culture conditions, it was discovered that small amounts of GH1-1 were secreted and cellodextrin was generated through trans-glycosylation activity of the secreted GH1-1. As GH1-1 does not have a secretion signal peptide, non-conventional protein secretion might facilitate the secretion of GH1-1. In cellobiose fermentations with S. cerevisiae expressing only GH1-1, knockout of TLG2 gene involved in non-conventional protein secretion pathway significantly delayed cellodextrin formation by reducing the secretion of GH1-1 by more than 50%. However, in cellobiose fermentations with S. cerevisiae expressing both GH1-1 and CDT-1, TLG2 knockout did not show a significant effect on cellodextrin formation, although secretion of GH1-1 was reduced by more than 40%. These results suggest that the development of new intracellular β-glucosidase, not influenced by non-conventional protein secretion, is required for better cellobiose fermentation performances of engineered S. cerevisiae fermenting cellobiose.

• Molecules and Cells
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• v.39 no.10
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• pp.756-761
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• 2016

We have identified 88 interactor candidates for human growth hormone (GH) by the yeast two-hybrid assay. Among those, we focused our efforts on carboxypeptidase E (CPE), which has been thought to play a key role in sorting prohormones, such as pro-opiomelanocortin (POMC), to regulated secretory vesicles. We found that CPE colocalizes with and interacts with GH in AtT20 pituitary cells. Downregulation of CPE led to decreased levels of GH secretion, consistent with involvement of CPE in GH sorting/secretion. Our binding assay in vitro with bacterially expressed proteins suggested that GH directly interacts with CPE but in a manner different from POMC.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.7
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• pp.1033-1037
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• 2008

The purpose of the present study was to investigate the effects of chromium picolinate (CrPic) on growth hormone (GH) secretion and pituitary GH mRNA expression in finishing pigs. Forty eight crossbred pigs with an initial body weight of 65.57 kg (SD = 1.05) were blocked by body weight and randomly assigned to two treatments with three replicates. Each group was fed the diet supplemented with or without $200{\mu}g/kg$ chromium from CrPic for 40 days. The results showed that average daily gain of pigs was increased by 9.84% (p<0.05), and longissimus muscle area was increased by 17.29% (p<0.05) with the supplementation of CrPic. The results of GH dynamic secretion showed that supplemental CrPic increased the mean level and peak value of GH by 36.58% (p<0.05) and 26.60% (p<0.05), respectively, while there was no significant effect on basal value, peak amplitude and peak duration. Pituitary mRNA expression of GH was not significantly influenced by supplemental CrPic. These results indicated that CrPic increased pigs GH secretion without change of pituitary GH mRNA expression.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.137-143
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• 1998

The effects of continuous GH(hGH) secretion on the female reproduction was studies in adults female transgenic rats expressing the hGH gene with a mouse whey acid protein (mWAP) promotor. Two line of transgenic female rats carrying the mWAP/hGH gene were established and used in the study. One was characterized by relatively high levels of serum hGH (high line), and the other had relatively low levels (low line). 1. High line female rats had recurring, Pseudopregancy-like estrous cycles accompanied by increased serum progesterone level for 2 weeks after ovulation, and they were fertile. 2. In the rats, luteinization occurred spontaneously without cervical stimulation, probably due to high levels of serum hGH, which has prolactin (PRL)-like activity in the rat. 3. Low line female rats had recurring, regular 4-days estrous PRL surge following cervical stimulation were not, detected and PRL secretion was not induced by a dopamine antagonist. 4. The ovarian tissue in this line had a much higher number of corpora lutea and grew much heavier than in normal littermates, suggesting impairment of PRL induced structural luteolized. Su, pp.ession of PRL secretion in the low line rats was, at least in part, due to a marked decrease in the number of lactotrophs in the pituitary. The present study shows that the serum hGH level plays a crucial role in regulating luteal function in female transgenic rats expressing the hGH gene.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.4
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• pp.306-308
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• 2001

A recombinant human growth hormone(hGH) was expressed as a secretory product in the yeast Saccharomyuces cerevisiae. There different leader sequences derived from the mating fac-tor $\alpha$1(MF$\alpha$1) inulinase and invertase were used to direct the secretion of hGH into the extracel-lular medium. Among three leader sequences tested, the inulinase leader sequence was found to be the most efficient in the secretory expression of hGH. In contrast, no hGH was detected in the ex-tracellular medium with the invertase leader sequence. After 48 h shake-flask culture, the yields of hGH secreted into th emedium by the invertase. MF$\alpha$1 inulinase and invertase leader sequences were approximately 0, 0.3 and 0.9 mg/L, respectively. The secretion efficiencies were also found to be 0, 3.8 and 13% for the invertase , MG$\alpha$1 and inulinase leader sequences, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.5
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• pp.757-766
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• 2002

Growth hormone-releasing peptide-2 (GHRP-2, also named KP102) is a new hexapeptide of a series of synthetic growth hormone-releasing peptides (GHRPs) which stimulates the secretion of growth hormone (GH) in vitro and in vivo in several species including calf, sheep and pig. The GH-releasing activity of GHRP-2 is two to three times more effective than that of the original GHRP-6, and GHRP-1 in the rats and humans. To date, GHRP-2 seems to be the most potent member of the family of GHRPs. Since the GHRPs are short peptides (5-7 amino acid residues), they are synthesized easily and are not as readily degraded in plasma as GHreleasing hormone (GHRH). These features ameliorate their potential on domestic animals because of their chemical nature the GHRPs are efficacious when administered i.v. orally or orally. However, studies in cow, pig and sheep do not indicate such a close relationship between GHRH, somatostatin (SS) and GH, calling into question the general applicability of the human and rat models. Perhaps there is an important role for an endogenous GHRP in the regulation of GH secretion in domestic animals. This review provides an overview on the current knowledge of physiological role of GHRP-2 in domestic animals.

• Journal of Life Science
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• v.22 no.9
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• pp.1243-1253
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• 2012

The production and secretion of growth hormone (GH) in the anterior pituitary gland can be induced by several natural products to control cell proliferation, differentiation, and migration. To investigate whether Chungkookjang (CKJ) produced by the fermentation process affects GH-related metabolism, the secretion and the response of GH were observed in pituitary cells and GH target cells. Among six CKJs manufactured by different strains of glycine max, only three CKJs, including Daewon (DW), Daepung (DP), and Taegwang (TG), induced GH secretion from GH3 cells at 5.0 mg/ml concentration. There were no significant changes detected in the viability of any of the cells treated with these CKJs. In addition, the increase in GH secretion from the GH3 cells was dependent on the concentration of the three types of CKJs. The proliferation of cell lines, including MG63 and HepG2 cells, that originated from those derived from the GH target organs was significantly activated by treatment with the GH-containing conditional medium (GCM) harvested from the three CKJ-treated GH3 cells, although their induction rate was different from each other. In these cells, p-STAT5 was maximally translocated into the nucleus of MG63 cells 30 min after DW treatment, while it was translocated in HepG2 cells at 60 min. These results suggest that these three types of CKJ could enhance the secretion of GH, as well as the GCM-derived response, in the two target organs.

• Fashion & Textile Research Journal
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• v.5 no.1
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• pp.77-81
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• 2003

The purpose of this study was to investigate the effect of multi-functional fabric on EEG and growth hormone (GH) during sleep and quality of sleep with the 9 young female athletes. The subjects participated in separated experimental procedure; sleeping in multi-functional fabric wear (experimental group) and cotton wear (control group) for 450min. During the night (22:00-05:30), we recorded the changes of nocturnal polysomnographic sleep recording and GH were measured every 60min. The results show that there are significant differences in percentage of stage 1, 2 and slow wave sleep (SWS) between two groups(S1, p<.05; S2, SWS, p<.01). The SWS percentage of experimental group is 1.89 times higher than control group. The changes of GH secretion varied depending on two experimental procedures. The peak of GH secretion in experimental group is more than controls by 2.4time (p<.001). The quality of sleep in experimetal group is significantly higher than control (p<.01). These results suggest muti-functional fabric wear is effective in inducing the deep sleep and increasing GH and quality of sleep.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.7
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• pp.1156-1168
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• 2007

The somatotropic (GH-IGF-I) axis consists of many hormonal and nutritional factors that control GH release from the somatotrophs in the anterior pituitary. The GH-releasing substances are GHRH and GHS (GHRP or ghrelin), while the GH release-inhibiting substances are somatostatin (SRIF), insulin-like growth factor-I (IGF-I), leptin and glucocorticoids. However, there is evidence showing that nutrition is involved in the control of the somatotropic axis. In addition, weaning is a drastic event for neonates because their alimentary and endocrine circumstances are changed due to the switch, even if gradual, from a liquid milk diet to one composed of such solids as hay and grains. The biological role of ghrelin is one of the hormonal factors that have been focused on ever since ghrelin was discovered at the end of the last century. A 27-amino acid peptide that is mainly synthesized and released from the abomasum epithelium, ghrelin has not been fully evaluated in relation to the somatotropic axis of the ruminant. It has also proven difficult even to investigate the cellular mechanisms of ghrelin action, because this hormone exerts animal-species-dependent actions via a complex set of intracellular signaling pathways. This is also the case for the action of leptin. Another substance, IGF-I, shows a partial inhibitory action on GH secretion in the ruminant. The effect of nutrition is also different among animal species. This is evident by the fact that undernutrition suppresses the circulating GH levels in rodents, but increases it in ruminants and humans. Recently, weaning has been shown to change the postprandial GH responses in ruminants; milk feeding increases, but hay and concentrate feeding suppress, the postprandial circulating GH levels. Even if the postprandial GH level is increased, the ghrelin level is decreased by milk feeding. Macronutrients also possess stimulatory and inhibitory actions on GH secretion in vivo and in vitro. These findings indicate the complexity of the control mechanisms of the somatotropic axis. In the present review, we summarize recent findings on the factors controlling the axis of the ruminant.

• Korean Journal of Animal Reproduction
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• v.22 no.2
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• pp.127-136
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• 1998

A chimeric gene comprising murine whey acidic protein(mWAP) and human growth hormone(hGH) was used to produce transgenic rats express hGH and secrete it into the blood. Two lines of transgenic rats carrying the mWAP/hGH construct were established; High line was characterized by relatively high levels of serum hGH, and low line had relatively low levels. The secretory profiles of rat GH(rGH) as well as hGH, the transgene product, were obtained in transgenic males and females of low line; both hGH and rGH serum levels were flattened with no episodic fluctuations, and the overall mean concentration of rGH was significantly lower than in normal littermates. Although the animals of High line showed an acceles, as assessed by vaginal opening and occurrence of first ovulation, advanced by 7∼8 days in both lines of animals. Accordingly, the body weight at puberty of low line transgenic females was much lower than that of normal littermates, indicating that continuous hGH expression could induce precocious puberty without enhancing the growth rate.