PHOSPHORYLATION OF ALZHEIMER-DISEASE AMYLOID PRECURSOR PEPTIDE BY PROTEIN KINASE-C AND CA-2+/CALMODULIN-DEPENDENT PROTEIN KINASE-II
PHOSPHORYLATION OF ALZHEIMER-DISEASE AMYLOID PRECURSOR PEPTIDE BY PROTEIN KINASE-C AND CA-2+/CALMODULIN-DEPENDENT PROTEIN KINASE-II
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DOI：
10.1073/pnas.85.16.6218
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发表时间：
1988-08-01
影响因子：
11.1
通讯作者：
GREENGARD, P
中科院分区：
文献类型：
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作者：
GANDY, S;CZERNIK, AJ;GREENGARD, P
阿尔茨海默病淀粉样蛋白前体（ADAP）的氨基酸序列已从相应的cDNA推导出，序列的亲水性分析表明具有单一跨膜结构域的受体样结构。ADAP的胞质结构域含有丝氨酸和苏氨酸磷酸化的潜在位点。在本研究中，合成的肽衍生自这个域被用作各种纯化的蛋白激酶的模型底物。蛋白激酶C快速催化Ser-655上ADAP的氨基酸残基645-661对应的肽[ADAP肽（645-661）]的磷酸化。Ca 2 +/钙调蛋白依赖性蛋白激酶II在Thr-654和Ser-655上磷酸化ADAP肽（645-661）。该肽作为cAMP依赖性蛋白激酶、cGMP依赖性蛋白激酶、酪蛋白激酶II或胰岛素受体蛋白酪氨酸激酶的底物几乎无效。当使用大鼠大脑皮层的匀浆作为蛋白激酶的来源时，钙/磷脂酰丝氨酸/二油酸甘油酯刺激ADAP肽（645-661）的磷酸化至高于磷酸化基础水平的4.6倍的水平，这与蛋白激酶C的显著刺激一致。使用用32 Pi预标记的大鼠大脑皮层突触体，32 Pi是一种32 P标记的磷蛋白，用抗ADAP肽（597-624）的抗血清免疫沉淀135 kDa，这与大鼠脑中ADAP的全型是磷蛋白的可能性一致。基于与表皮生长因子受体和白细胞介素2受体的胞质结构域中的质膜残基的蛋白激酶C磷酸化作用的类比，ADAP的磷酸化可能靶向其内化。
The amino acid sequence of the Alzheimer disease amyloid precursor (ADAP) has been deduced from the corresponding cDNA, and hydropathy analysis of the sequence suggests a receptor-like structure with a single transmembrane domain. The putative cytoplasmic domain of ADAP contains potential sites for serine and threonine phosphorylation. In the present study, synthetic peptides derived from this domain were used as model substrates for various purified protein kinases. Protein kinase C rapidly catalyzed the phosphorylation of a peptide corresponding to amino acid residues 645-661 of ADAP [ADAP peptide (645-661)] on Ser-655. Ca2+/calmodulin-dependent protein kinase II phosphorylated ADAP peptide(645-661) on Thr-654 and Ser-655. This peptide was virtually ineffective as a substrate for cAMP-dependent protein kinase, cGMP-dependent protein kinase, casein kinase II, or insulin receptor protein-tyrosine kinase. When a homogenate of rat cerebral cortex was used as the source of protein kinase, phosphorylation of ADAP peptide(645-661) was stimulated by calcium/phosphatidylserine/diolein to a level 4.6-fold above the basal level of phosphorylation, consistent with a prominent stimulation by protein kinase C. Using rat cerebral cortex synaptosomes prelabeled with 32Pi, a 32P-labeled phosphoprotein of .apprxeq. 135 kDa was immunoprecipitated by using antisera prepared against ADAP peptide(597-624), consistent with the possibility that the holoform of ADAP in rat brain is a phosphoprotein. Based on analogy with the effect of phosphorylation by protein kinase C of juxtamembrane residues in the cytoplasmic domain of the epidermal growth factor receptor and the interleukin 2 receptor, phosphorylation of ADAP may target it for internalization.