Gene type: protein coding.
Gene size: 7604 bp, 7 exons.

mRNA 2366 bp (length may vary for alternative splicing forms).
There are 5 transcripts (Ensembl).

Name	Transcript ID	Length (bp)	Protein ID	Length (aa)	Exon
IGSF8-001	ENST00000314485	2343	ENSP00000316664	613	7
IGSF8-002	ENST00000448417	1059	ENSP00000397464	301	4
IGSF8-003	ENST00000368086	2366	ENSP00000357065	613	7
IGSF8-201	ENST00000358475	2004	ENSP00000351261	526	8
IGSF8-004	ENST00000460351	876	No protein product	-	2

There are 7 putative alternative splicing forms (AceView).

IGSF8 alternative variant	mRNA size (bp)	Exons	NCBI 36, March 2006 genome (kb)	Aa	Protein size (kDa)	pI
aApr07	2352	7	7.36	674	71.8	8.2
bApr07	2304	8	7.60	664	70.4	8.3
cApr07	1995	4	2.92	311	32.7	8.2
dApr07	1005	4	5.58	283	30.5	6.7
eApr07-unspliced	6184	1	6.18	166	18.1	6.7
fApr07 (partial mRNA)	571	4	4.71	165	17.9	7.3
variant gApr07-unspliced (partial mRNA)	581	1	0.58 Appear non coding	91 Appear non coding	9.6 Appear non coding	11.5 Appear non coding

IGSF8-004, an alternative splicing form of IGSF8/CD316, is predicted to have no protein product (Ensembl).

613 amino acids, molecular weight is 65034 Da.
Basal isoelectric point: 8.23 (

CD316 mRNA is ubiquitously expressed in human tissues, with high expression in brain, kidney, testis, liver and placenta, with low expression in peripheral blood cells, lung, and skeletal muscle.
CD316 protein is highly expressed in human brain (cortex, white matter, hippocampus and cerebellum), astrocytes, hepatocytes and lymphoid cells (majority of B-cells, T-cells and natural killer cells, but not on monocytes, polynuclear cells and platelets). CD316 is constitutively expressed on plasmacytoid dendritic cells and on cord blood-derived Langerhans-like cells. Upon stimulation, CD316 is expressed on monocytes, monocytes derived dendritic cells and myeloid dendritic cells.

Plasma membrane, cell-cell contacts, microvilli.

1. Suppresses cell movement and cell aggregation.
2. Regulates integrin alpha3beta1- and alpha4beta1-dependent cell morphology and cell spreading.
3. May participate in the regulation of neurite outgrowth and maintenance of the neural network in the adult brain.
4. Interacts with its ligand, HSPA8, and may influence the behavior of dendritic cells and control adaptive immune response.
5. Links tetraspanin web to the actin cytoskeleton through direct associations with ezrin-radixin-moesin proteins.
6. Inhibits glioblastoma growth in vitro and in vivo.
7. EWI-2 wint inhibits hepatitis C virus entry.
8. May play a role in fertilization. Lack of CD316 present at the cell surface of CD9-null oocytes may contribute to the loss of ability of CD9-null oocytes to fuse with sperms.

CD316 typically inhibits cell migration and negatively regulates cell proliferation. It associates with tetraspanins CD9, CD81, and CD82 and likely contributes to various functions of these associated tetraspanins. It also regulates the functions of alpha3beta1 and alpha4beta1 integrins, probably through its associated tetraspanins (Clark et al., 2001; Stipp et al., 2001; Stipp et al., 2003; Zhang et al., 2003; Kolesnikova et al., 2004; Kolesnikova et al., 2009; Sala-Valdés et al., 2006).

CD316 protein is conserved in chimpanzee, cow, mouse, rat, and zebrafish and belongs to the EWI subfamily of Ig superfamily. Other human EWI subfamily proteins include FPRP/CD9P-1, IGSF3, and CD101.

Currently there is no known disease-related or biologically significant mutation (see HGMD).