描述:
CCL4, also known as MIP1β, is a 12 kDa β chemokine that is secreted by activated leukocytes,
lymphocytes, vascular endothelial cells, and pulmonary smooth muscle cells. CCL4 interacts
with CCR5 to attract lymphocytes, NK cells, and immature dendritic cells to sites of
inflammation. CCL4 also blocks the entry of HIV into CCR5expressing cells. Human CCL4 and
its variants are encoded by two paralogous genes, one of which (SCYA4) encodes CCL4 itself.
The other gene (SCYA4L) is found in two alleles that give rise to CCL4L1 and CCL4L2,
respectively. The human CCL4L1 cDNA encodes a 92 amino acid (aa) precursor with a 23 aa
signal sequence. Alternate splicing yields an isoform with a 40 aa internal deletion. The second
allele (SCYA4L2), encoding CCL4L2, is spliced into a variety of isoforms (9). Human CC4L1 shares
greater than 98% aa sequence identity with CCL4 and CCL4L2. It shares 96% aa sequence
identity with rhesus CCL4 and approximately 80 90% aa sequence identity with bovine, mouse,
rabbit, and rat CCL4. The gene copy number for CCL4L1 varies from zero to five, but this is not
associated with changes in mRNA or protein levels. CCL4 and CCL4L1 demonstrate comparable
CCR5 binding, promotion of chemotaxis, and inhibitionof HIV replication in stimulated PBMC.
In vivo, the first two Nterminal amino acids of CCL4 are removed by DPPIV. The truncated form
is as active as fulllength CCL4 and gains the ability to bind CCR1 and CCR2b. Similar proteolytic
processing of CCL4L1 has not been described.
原厂资料:
CCL4, also known as MIP1β, is a 12 kDa β chemokine that is secreted by activated leukocytes,
lymphocytes, vascular endothelial cells, and pulmonary smooth muscle cells. CCL4 interacts
with CCR5 to attract lymphocytes, NK cells, and immature dendritic cells to sites of
inflammation. CCL4 also blocks the entry of HIV into CCR5expressing cells. Human CCL4 and
its variants are encoded by two paralogous genes, one of which (SCYA4) encodes CCL4 itself.
The other gene (SCYA4L) is found in two alleles that give rise to CCL4L1 and CCL4L2,
respectively. The human CCL4L1 cDNA encodes a 92 amino acid (aa) precursor with a 23 aa
signal sequence. Alternate splicing yields an isoform with a 40 aa internal deletion. The second
allele (SCYA4L2), encoding CCL4L2, is spliced into a variety of isoforms (9). Human CC4L1 shares
greater than 98% aa sequence identity with CCL4 and CCL4L2. It shares 96% aa sequence
identity with rhesus CCL4 and approximately 80 90% aa sequence identity with bovine, mouse,
rabbit, and rat CCL4. The gene copy number for CCL4L1 varies from zero to five, but this is not
associated with changes in mRNA or protein levels. CCL4 and CCL4L1 demonstrate comparable
CCR5 binding, promotion of chemotaxis, and inhibitionof HIV replication in stimulated PBMC.
In vivo, the first two Nterminal amino acids of CCL4 are removed by DPPIV. The truncated form
is as active as fulllength CCL4 and gains the ability to bind CCR1 and CCR2b. Similar proteolytic
processing of CCL4L1 has not been described.