盐胁迫下拟南芥SCAMP基因克隆和表达的生物信息学分析

为探究分泌载体膜蛋白（Secretory carrier membrane protein, SCAMP）的功能，采用PCR方法从模式植物拟南芥中克隆到5个SCAMP基因，进行生物信息学分析，并通过实时荧光定量PCR技术分析5个SCAMP基因在盐胁迫下的表达模式。结果显示，拟南芥SCAMP蛋白的相对分子量为30.1~33.2 kDa，等电点为6.60~9.18，属于不稳定性疏水蛋白，二级蛋白结构中主要包含4种构象:α–螺旋（Alpha helix， Hh）、无规则卷曲（Randon coil， Cc）、直链延伸（Extended strand，Ee）和β–折叠（Beta turn，Tt），其中以α–螺旋为主，包含4个跨膜结构域，N端和C端均在细胞膜内。实时荧光定量PCR结果表明，AtSCAMPs的表达量均受盐胁迫诱导上调表达，AtSCAMP1，AtSCAMP3，AtSCAMP4，AtSCAMP5基因在叶中的表达明显高于根，且AtSCAMP4和AtSCAMP5在叶中受盐胁迫变化最明显。

Cloning and Bioinformatics Analysis of SCAMP Genes from Arabidopsis thaliana under Salt Stress

To investigate the role of secretory carrier membrane protein (SCAMP), five SCAMP genes were cloned from Arabidopsis thaliana by PCR method for bioinformatics analysis, and their expression under salt stress was analyzed by using the real time quantitative PCR (qRT-PCR). Bioinformatics analysis showed that the AtSCAMP proteins have a molecular weight of 30.1-33.2 kDa with an isoelectric point (pI) of 6.60-9.18, and hence belong to unstable hydrophobic proteins. The secondary structure of the AtSCAMP proteins contains four conformations: α-helix (Hh), random coil (Cc), extended strand (Ee) and β-turn (Tt), of which α-helix is the main part. There are four transmembrane domains in the AtSCAMP proteins, and the N-terminus and C-terminus are located in the cell membrane. The qRT-PCR results showed that the expression of the AtSCAMP genes was all up-regulated in response to salt stress. The expression of AtSCAMP1, AtSCAMP3, AtSCAMP4 and AtSCAMP5 was higher in the leaves of A. thaliana than in the roots, and the most significant changes were found in the expression of AtSCAMP4 and AtSCAMP5 in leaves under salt stress.