SLC3A2

4F2 cell-surface antigen heavy chain is a is_associated_with::protein that in humans is encoded by the SLC3A2 (solute carrier family 3 member 2) is_associated_with::gene.

SLC3A2 comprises the light subunit of the large neutral amino acid transporter (LAT1) that is also known as is_associated_with::CD98 (cluster of differentiation 98).

Function
SLC3A2 is a member of the is_associated_with::solute carrier family and encodes a cell surface, transmembrane protein with an is_associated_with::alpha-amylase domain. The protein exists as the heavy chain of a heterodimer, covalently bound through di-sulfide bonds to one of several possible light chains. It associates with integrins and mediates integrin-dependent signaling related to normal cell growth and tumorigenesis. Alternate transcriptional splice variants, encoding different isoforms, have been characterized.

LAT1 is a heterodimeric is_associated_with::membrane transport protein that preferentially transports neutral branched (is_associated_with::valine, is_associated_with::leucine, is_associated_with::isoleucine) and aromatic (is_associated_with::tryptophan, is_associated_with::tyrosine) is_associated_with::amino acids. LAT is highly expressed in brain is_associated_with::capillaries (which form the is_associated_with::blood brain barrier) relative to other tissues.

A functional LAT1 transporter is composed of two proteins encoded by two distinct genes:
 * 4F2hc/CD98 heavy subunit protein encoded by the SLC3A2 gene (this gene)
 * CD98 light subunit protein encoded by the is_associated_with::SLC7A5 gene

Interactions
SLC3A2 has been shown to interact with is_associated_with::SLC7A7.