The CKLF-like MARVEL transmembrane domain-containing family (CMTM), previously termed the chemokine-like factor superfamily (CKLFSF), consists of 9 proteins, some of which have various
isoforms due to
alternative splicing
Alternative splicing, or alternative RNA splicing, or differential splicing, is an alternative splicing process during gene expression that allows a single gene to code for multiple proteins. In this process, particular exons of a gene may be ...
of their respective genes. These proteins
along with their isoforms
are:
*
Chemokine-like factor (CKLF), the founding member of this family, has 4 known isoforms, CKLF1 to CKLF4.
*
CKLF like MARVEL transmembrane domain-containing 1 (CMTM1) has 23 known isoforms, CMTM1-v1 to CMTM1-v23.
*
CKLF like MARVEL transmembrane domain-containing 2 (CMTM2) has no known isoforms.
*
CKLF like MARVEL transmembrane domain-containing 3 (CMTM3) has no known isoforms.
*
CKLF like MARVEL transmembrane domain-containing 4 (CMTM4) has 3 known isoforms, CMTM4-v1 to CMTM4-v3.
*
CKLF-like MARVEL transmembrane domain-containing 5 (CMTM5) has 6 known isoforms, CMTM5-v1 to CMTM5-v6.
*
CKLF like MARVEL transmembrane domain containing 6 (CMTM6) has no known isoforms.
*
CKLF like MARVEL transmembrane domain containing 7 (CMTM7) has 2 isoforms, CMTM7-v1 and CMTM7-v2.
*
CKLF like MARVEL transmembrane domain-containing 8 (CMTM8) has two isoforms, CMTM8 and CMTM8-v2 (Little is known about the CMTM8-v2 isoform and the CMTM8 isoform is referred to as CMTM8 rather than CMTM8-v1.
).
All of these proteins have
domains (i.e. regions) similar to analogous domains in the
chemokine proteins;
tetraspanin proteins (also termed transmembrane-4 superfamily proteins);
myelin and lymphocyte protein (also termed MAR protein); proteins that direct
membrane vesicle trafficking; and other proteins that are embedded in cell membranes.
The
genes encoding (i.e. directing the production of) these proteins, ''CKLF, CMTM1, CMTM2, CMTM3, CMTM4, CMTM5, CMTM6, CMTM7,'' and ''CMTM8'', respectively, also share similar regions that encode the domains just cited for their proteins. (The 8 CMTM genes were formerly termed CKLFSF1, CKLFSF2, CKLFSF3, CKLFSF4, CKLFSF5, CKLFSF6, CKLFSF7, and CKLFSF8.) The ''CKLF, CMTM1, CMTM2, CTMT3,'' and ''CMTM4'' genes
cluster
may refer to:
Science and technology Astronomy
* Cluster (spacecraft), constellation of four European Space Agency spacecraft
* Asteroid cluster, a small asteroid family
* Cluster II (spacecraft), a European Space Agency mission to study th ...
together in
band 22 on the
long (i.e. "q") arm of
chromosome 16; the ''CMTM6, CMTM7,'' and ''CMTM8'' genes form a second cluster in band 22 on the short (i.e. "p") of
chromosome 3; and the ''CMTM5'' gene, located in band 11.2 on the q arm of
chromosome 14, is not clustered with the other CMTM genes. These structural similarities and clusterings reflect the close relationships of these proteins and genes.
Studies suggest that the members of this family may be involved in the development of various cancers
autoimmune diseases
An autoimmune disease is a condition arising from an abnormal immune response to a functioning body part. At least 80 types of autoimmune diseases have been identified, with some evidence suggesting that there may be more than 100 types. Nearly a ...
,
,
the
male reproductive system,
and
angiogenesis
Angiogenesis is the physiological process through which new blood vessels form from pre-existing vessels, formed in the earlier stage of vasculogenesis. Angiogenesis continues the growth of the vasculature by processes of sprouting and splitting ...
(i.e. development of new blood vessels from pre-existing blood vessels).
In most of these cases, however, further studies are needed to determine if these CMTM proteins and/or their corresponding genes and
mRNAs will be promising targets to help in the diagnosis, prognosis, and/or treatment of these disorders.
References
{{reflist
Human proteins
DNA replication
Gene expression
Transcription coregulators