Chen Xiaoliang, Ding Hong
Second People Hospital of Hangzhou, No. 1 Wenzhou Road, Hangzhou 310015, China.
Exp Diabetes Res. 2011;2011:421982. doi: 10.1155/2011/421982. Epub 2011 Jul 13.
The tail-anchored membrane protein, sarcolemmal membrane associated protein (SLMAP) is encoded to a single gene that maps to the chromosome 3p14 region and has also been reported in certain diabetic populations. Our previous studies with db/db mice shown that a deregulation of SLMAP expression plays an important role in type 2 diabetes. Male Tally Ho mice were bred to present with either normoglycemia (NG) or hyperglycemia (HG). Abdominal adipose tissue from male Tally Ho mice of the HG group was found to have a significantly lower expression of the membrane associated glucose transporter-4 (GLUT-4) and higher expression of SLMAP compared to tissue from NG mice. There were 3 isoforms expressed in the abdominal adipose tissue, but only 45 kDa isoform of SLMAP was associated with the GLUT-4 revealed by immunoprecipitation data. Knock down studies using SLMAP siRNA with adipocytes resulted in a significant reduction in SLMAP and a decrease in glucose uptake. Thus, SLMAP may be an important regulator of glucose uptake or involved in GLUT-4 fusion/translocation into the plasma membrane of mouse abdominal adipose tissue and changes in SLMAP expression are linked to hyperglycemia and diabetes.
尾锚定膜蛋白，即肌膜相关蛋白（SLMAP），由一个定位在3号染色体p14区域的单一基因编码，在某些糖尿病群体中也有相关报道。我们之前对db/db小鼠的研究表明，SLMAP表达失调在2型糖尿病中起重要作用。将雄性塔利霍小鼠培育成具有正常血糖（NG）或高血糖（HG）的状态。与NG小鼠的组织相比，HG组雄性塔利霍小鼠的腹部脂肪组织中膜相关葡萄糖转运蛋白4（GLUT-4）的表达显著降低，而SLMAP的表达更高。在腹部脂肪组织中表达了3种异构体，但免疫沉淀数据显示，只有45 kDa的SLMAP异构体与GLUT-4相关。使用SLMAP siRNA对脂肪细胞进行敲低研究导致SLMAP显著减少，葡萄糖摄取减少。因此，SLMAP可能是葡萄糖摄取的重要调节因子，或参与GLUT-4向小鼠腹部脂肪组织质膜的融合/转运，且SLMAP表达的变化与高血糖和糖尿病有关。
