循环整合素：α5β1、α6β4和Mac-1，但不包括α3β1、α4β1或淋巴细胞功能相关抗原-1（LFA-1）。

Medical Research Council, Laboratory of Molecular Biology, Cambridge, UK.

EMBO J. 1992 Feb;11(2):405-10. doi: 10.1002/j.1460-2075.1992.tb05068.x.

The alpha 5 beta 1, alpha 6 beta 4 and Mac-1 integrins all participate in the endocytotic cycle. By contrast, alpha 3 beta 1, alpha 4 beta 1 and LFA-1 do so much more slowly, or not at all, in the cell lines examined. This indicates that the alpha-chains appear to determine whether an integrin cycles or not, and that alpha 5 beta 1, alpha 6 beta 4 and Mac-1 can be brought to the leading edge of a moving cell by endocytosis and recycling.

α5β1、α6β4和Mac-1整合素均参与内吞循环。相比之下，在检测的细胞系中，α3β1、α4β1和淋巴细胞功能相关抗原-1（LFA-1）的内吞循环速度要慢得多，或者根本不发生内吞循环。这表明α链似乎决定了整合素是否进行循环，并且α5β1、α6β4和Mac-1可以通过内吞作用和再循环被带到移动细胞的前沿。