PSEN2(Presenilin 2)是早老素家族(Presenilin gene family)的成员之一,与PSEN1共同构成γ-分泌酶复合体的核心催化亚基。该基因家族的主要共性是参与跨膜蛋白的切割,尤其是淀粉样前体蛋白(APP)的加工,从而影响阿尔茨海默病(AD)的关键病理特征——β-淀粉样蛋白(Aβ)的生成。PSEN2位于1号染色体上,其表达产物是一种具有9个跨膜结构域的蛋白质,主要分布于内质网和高尔基体等细胞器膜上,通过调控γ-分泌酶的活性影响Notch信号通路、细胞凋亡及钙离子稳态等生理过程。PSEN2的功能突变(如N141I、M239V等)会改变γ-分泌酶的切割特异性,导致毒性Aβ42片段过度产生,促进淀粉样斑块沉积,与家族性阿尔茨海默病(FAD)的早发型密切相关。此外,PSEN2突变还可能影响线粒体功能,加剧神经元氧化应激和突触损伤。若PSEN2表达降低,可能通过减少Aβ生成缓解AD病理,但会干扰Notch依赖的细胞分化;而过表达则可能加速神经退行性变,并可能通过异常钙信号诱发细胞凋亡。与PSEN1相比,PSEN2在脑组织中的表达量较低,但其突变导致的AD进展通常更缓慢,提示其在疾病中可能存在补偿机制。除神经退行性疾病外,PSEN2还与某些癌症(如乳腺癌)的转移抑制相关,可能通过调节上皮-间质转化(EMT)发挥作用。研究还发现PSEN2与自噬和溶酶体功能存在交叉调控,进一步扩展了其在细胞稳态维持中的多重角色。
Alzheimer's disease (AD) patients with an inherited form of the disease carry mutations in the presenilin proteins (PSEN1 or PSEN2) or the amyloid precursor protein (APP). These disease-linked mutations result in increased production of the longer form of amyloid-beta (main component of amyloid deposits found in AD brains). Presenilins are postulated to regulate APP processing through their effects on gamma-secretase, an enzyme that cleaves APP. Also, it is thought that the presenilins are involved in the cleavage of the Notch receptor such that, they either directly regulate gamma-secretase activity, or themselves act are protease enzymes. Two alternatively spliced transcript variants encoding different isoforms of PSEN2 have been identified. [provided by RefSeq, Jul 2008]
阿尔茨海默氏病(AD)患者在早老蛋白的疾病进位突变(PSEN1或PSEN2)或淀粉样前体蛋白(APP)的一种遗传形式。这些疾病相关的突变导致生产淀粉样蛋白-β(公元大脑中淀粉样蛋白沉积的主要成分)的较长形式的增加。早老被假定通过其对γ-分泌酶的作用来调节APP处理,酶劈开APP。此外,可以认为,在早老参与Notch受体的裂解,使得它们可以直接调节γ-分泌酶活性,或本身的行为是蛋白酶。两个可变剪接转录变异体PSEN2的编码不同亚型已经确定。 [由RefSeq的,2008年7月提供]
PSEN2基因(以及对应的蛋白质)的细胞分布位置:
PSEN2基因的本体(GO)信息:
名称 |
---|
4330 Notch signaling pathway [PATH:hsa04330] |
4722 Neurotrophin signaling pathway [PATH:hsa04722] |
5010 Alzheimer's disease [PATH:hsa05010] |
名称 |
---|
A third proteolytic cleavage releases NICD |
Activated NOTCH1 Transmits Signal to the Nucleus |
Axon guidance |
Cell death signalling via NRAGE, NRIF and NADE |
Constitutive Signaling by NOTCH1 HD+PEST Domain Mutants |
Constitutive Signaling by NOTCH1 PEST Domain Mutants |
Developmental Biology |
Disease |
Diseases of signal transduction |
EPH-ephrin mediated repulsion of cells |
EPH-Ephrin signaling |
NOTCH2 Activation and Transmission of Signal to the Nucleus |
NRIF signals cell death from the nucleus |
Nuclear signaling by ERBB4 |
p75 NTR receptor-mediated signalling |
Regulated proteolysis of p75NTR |
Signaling by ERBB4 |
Signaling by NOTCH |
Signaling by NOTCH1 |
Signaling by NOTCH1 HD+PEST Domain Mutants in Cancer |
Signaling by NOTCH1 in Cancer |
Signaling by NOTCH1 PEST Domain Mutants in Cancer |
Signaling by NOTCH2 |
Signaling by NOTCH3 |
Signaling by NOTCH4 |
Signalling by NGF |
疾病名称 | 关系值 | NofPmids | NofSnps | 来源 |
ALZHEIMER DISEASE 4 | 0.36 | 3 | 9 | CLINVAR_CTD_human_UNIPROT |
Alzheimer's Disease | 0.312520889 | 58 | 4 | BeFree_CLINVAR_CTD_human_GAD_LHGDN |
Cardiomyopathy, Dilated, 1V | 0.24 | 0 | 1 | CLINVAR_CTD_human |
Cardiomyopathy, Dilated | 0.120271442 | 1 | 0 | BeFree_CTD_human |
Asphyxia Neonatorum | 0.12 | 1 | 0 | CTD_human |
Malignant neoplasm of breast | 0.010314791 | 38 | 0 | BeFree |
Breast Carcinoma | 0.009500466 | 35 | 1 | BeFree |
Dementia | 0.008620127 | 14 | 3 | BeFree_GAD_LHGDN |
Familial Alzheimer Disease (FAD) | 0.005428837 | 20 | 2 | BeFree |
Frontotemporal dementia | 0.003724241 | 6 | 3 | BeFree_GAD |
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