interleukin-16; lymphocyte chemoattractant factor (IL16, IL-16)

^[1]^[2]^[3]

Function

stimulates a migratory response in CD4+ lymphocytes, monocytes, & eosinophils
primes CD4+ T-cells for IL-2 & IL-15 responsiveness
induces T-lymphocyte expression of interleukin 2 receptor
ligand for CD4
precursor protein interacts with PPP1R12A
isoform 1 may act as a scaffolding protein that anchors ion channels in the membrane
isoform 3 is involved in cell cycle progression in T-cells
appears to be involved in transcriptional regulation of SKP2
probably part of a transcriptional repression complex on the core promoter of the SKP2 gene
may act as a scaffold for GABPB1 (DNA-binding subunit of the GABP transcription factor complex) & HDAC3 thus maintaining transcriptional repression & blocking cell cycle progression in resting T-cells
isoform 3 is synthesized as a chemo-attractant inactive precursor in hemopoietic tissues & is proteolytically cleaved by caspase-3 to yield IL-16
isoform 3 interacts (via PDZ 3 domain) with PPP1R12A, PPP1R12B & PPP1R12C
isoform 1 interacts with PPP1R12B
isoform 3 interacts with GRIN2A
isoform 3 interacts with GABPB1
isoform 3 interacts (via PDZ 3 domain) with HDAC3
isoform 1 interacts with GRIN2D, KCNJ10, KCNJ15 & CACNA1C (putative)
isoform 3 interacts with HTLV-1 Tax

isoform 3 is expressed in hemopoietic tissues, such as resting T-cells, but is undetectable during active T-cell proliferation
isoform 3 is down-regulated in T-cells after TCR activation