Journal of Genetics and Genomics

Expression of the human TSPY gene in the brains of transgenic mice suggests a potential role of this Y chromosome gene in neural functions

Tatsuo Kido, Stephanie Schubert, Jörg Schmidtke, Yun-Fai Chris Lau

2011, 38(5): 181-191. doi: 10.1016/j.jgg.2011.04.002

Abstract (67) HTML PDF (0)

Abstract:
The testis specific protein Y-encoded (TSPY) is a member of TSPY/SET/NAP1 superfamily, encoded within the gonadoblastoma locus on the Y chromosome. TSPY shares a highly conserved SET/NAP-domain responsible for protein–protein interaction among TSPY/SET/NAP1 proteins. Accumulating data, so far, support the role of TSPY as the gonadoblastoma gene, involved in germ cell tumorigenesis. The X-chromosome homolog of TSPY, TSPX is expressed in various tissues at both fetal and adult stages, including the brain, and is capable of interacting with the multi-domain adapter protein CASK, thereby influencing the synaptic and transcriptional functions and developmental regulation of CASK in the brain and other neural tissues. Similar to TSPX, we demonstrated that TSPY could interact with CASK at its SET/NAP-domain in cultured cells. Transgenic mice harboring a human TSPY gene and flanking sequences showed specific expression of the human TSPY transgene in both testis and brain. The neural expression pattern of the human TSPY gene overlapped with those of the endogenous mouse Cask and Tspx gene. Similarly with TSPX, TSPY was co-localized with CASK in neuronal axon fibers in the brain, suggesting a potential role(s) of TSPY in development and/or physiology of the nervous system.

Pioglitazone suppresses advanced glycation end product-induced expression of plasminogen activator inhibitor-1 in vascular smooth muscle cells

Xiaochen Yuan, Naifeng Liu

2011, 38(5): 193-200. doi: 10.1016/j.jgg.2011.04.001

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Abstract:
Advanced glycation end products (AGEs) play an important role in vascular complications of diabetes, including fibrinolytic abnormalities. Pioglitazone, a peroxisome proliferator-activated receptor gamma (PPARγ) agonist, has recently been shown to reduce circulating plasminogen activator inhibitor-1 (PAI-1) levels in diabetes mellitus. In the present study, we investigated the effects of pioglitazone on the expression of local PAI-1 in rat vascular smooth muscle cells (VSMCs) induced by AGEs and the underlying mechanism. The result showed that AGEs could enhance the PAI-1 expression by 5.1-fold in mRNA and 2.7-fold in protein level, as evaluated by real-time RT-PCR and Western blotting, respectively. Pioglitazone was found to down-regulate the AGE-stimulated PAI-1 expression in VSMCs. However, these inhibitory effects were partially attenuated by the PPARγ antagonist, GW9662. Furthermore, we found that AGEs induced a rapid increase in phosphorylation and activation of extracellular signal-regulated protein kinase 1/2 (ERK1/2). The ERK kinase inhibitor, U0126, partially prevented the induction of PAI-1 by AGEs. Moreover, pioglitazone was also found to inhibit the phosphorylation of ERK1/2. Taken together, it was concluded that pioglitazone could inhibit AGE-induced PAI-1 expression, which was mediated by the ERK1/2 and PPARγ pathways. Our findings suggested pioglitazone had a therapeutic potential in improving fibrinolytic activity, and consequently preventing thromboembolic complications of diabetes and cardiovascular disease.

Coevolution study of mitochondria respiratory chain proteins: Toward the understanding of protein–protein interaction

Ming Yang, Yan Ge, Jiayan Wu, Jingfa Xiao, Jun Yu

2011, 38(5): 201-207. doi: 10.1016/j.jgg.2011.04.003

Abstract (69) HTML PDF (1)

Abstract:
Coevolution can be seen as the interdependency between evolutionary histories. In the context of protein evolution, functional correlation proteins are ever-present coordinated evolutionary characters without disruption of organismal integrity. As to complex system, there are two forms of protein–protein interactions in vivo, which refer to inter-complex interaction and intra-complex interaction. In this paper, we studied the difference of coevolution characters between inter-complex interaction and intra-complex interaction using “Mirror tree” method on the respiratory chain (RC) proteins. We divided the correlation coefficients of every pairwise RC proteins into two groups corresponding to the binary protein–protein interaction in intra-complex and the binary protein–protein interaction in inter-complex, respectively. A dramatical discrepancy is detected between the coevolution characters of the two sets of protein interactions (Wilcoxon test, p-value = 4.4 × 10⁻⁶). Our finding reveals some critical information on coevolutionary study and assists the mechanical investigation of protein–protein interaction. Furthermore, the results also provide some unique clue for supramolecular organization of protein complexes in the mitochondrial inner membrane. More detailed binding sites map and genome information of nuclear encoded RC proteins will be extraordinary valuable for the further mitochondria dynamics study.

A Pid3 allele from rice cultivar Gumei2 confers resistance to Magnaporthe oryzae

Jie Chen, Yongfeng Shi, Wenzheng Liu, Rongyao Chai, Yaping Fu, Jieyun Zhuang, Jianli Wu

2011, 38(5): 209-216. doi: 10.1016/j.jgg.2011.03.010

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Abstract:
Rice blast, caused by Magnaporthe oryzae, is one of the most devastating diseases. Using map-based strategy and in silico approach we isolated a new rice (Oryza sativa L.) blast resistance allele of Pid3, designated Pi25, from a stable blast resistance cultivar Gumei2. Over-expression analysis and complementation test showed thatPi25 conferred blast resistance to M. oryzae isolate js001-20. Sequence analysis showed that Pi25 was an intronless gene of 2772 nucleotides with single nucleotide substitution in comparison to Pid3 at the nucleotide position 459 and predicatively encoded a typical coiled coil–nucleotide binding site–leucine rich repeat (CC–NBS–LRR) protein of 924 amino acid residuals with 100% identity to Pid3 putative protein. The susceptible allele pi25 in Nipponbare contained a nonsense mutation at the nucleotide position 2209 resulting in a truncated protein with 736 amino acid residuals. In addition, 14 nucleotide substitutions resulting in 10 amino acid substitutions were identified between Pi25 and pi25 upstream the premature stop codon in the susceptible allele. Although the mechanism of Pi25/Pid3-mediated resistance needs to be further investigated, the isolation of the allele would facilitate the utilization of Pi25/Pid3 in rice blast resistance breeding program via transgenic approach and marker assisted selection.

Introgression of qPE9-1 allele, conferring the panicle erectness, leads to the decrease of grain yield per plant in japonica rice (Oryza sativa L.)

Xiuhua Yi, Zujian Zhang, Shengyuan Zeng, Chunyan Tian, Juncheng Peng, Min Li, Yue Lu, Qingcai Meng, Minghong Gu, Changjie Yan

2011, 38(5): 217-223. doi: 10.1016/j.jgg.2011.03.011

Abstract (105) HTML PDF (2)

Abstract:
Panicle architecture is closely related to yield formation. The qPE9-1 gene has been proved to be widely used in high-yield rice cultivar developments, conferring erect panicle character in japonica rice. Recently, qPE9-1 has been successfully cloned; however, the genetic effect on grain yield per plant of the erect panicle allele qPE9-1 is controversial yet. In the present study, a drooping panicle parent Nongken 57, carrying qpe9-1 allele, was used as recurrent parent to successively backcross to a typical erect panicle line from the double haploid (DH) population (Wuyunjing 8/Nongken 57), which was previously shown to carry qPE9-1 allele. Thus a pair of near-isogenic lines (NILs) was developed. The comparison of agronomic traits between the NILs showed that, when qpe9-1 was replaced by qPE9-1, the panicle architecture was changed from drooping to erect; moreover, the panicle length, plant height, 1000-grain weight and the tillers were significantly decreased, consequently resulting in the dramatic decrease of grain yield per plant by 30%. Therefore, we concluded that the qPE9-1 was a major factor controlling panicle architecture, and qPE9-1 had pleiotropic nature, with negative effects on grain yield per plant. This result strongly suggests that the erect panicle allele qPE9-1 should be used together with other favorable genes in the high-yield breeding practice. In addition, the effect of qPE9-1 on eating and cooking quality was also discussed in the present study.

2011 Vol. 38, No. 5