Disease relevance of LRRC32

• 11q13 alterations in two cases of hibernoma: large heterozygous deletions and rearrangement breakpoints near GARP in 11q13.5 [1].
• As a tribute to the complexity of the amplification events involving 11q13 sequences in human breast cancer, we have now studied a more telomeric region at 11q13.5-q14 defined by a new transcription unit, D11S833E [2].

High impact information on LRRC32

• We have observed that amplicons present in cell lines and primary tumors amplified for both BCL1 and D11S833E could be interrupted between these two loci [2].

Biological context of LRRC32

• GARP comprises two coding exons, is expressed as two major transcripts of 4.4 and 2.8 kilobases, respectively, and encodes a putative transmembrane protein of 662 amino acids, the extracellular portion of which is almost entirely made of leucine-rich repeats [3].
• The mouse GARP deduced amino-acid sequence is highly similar to that of the human protein [4].
• GARP/LRRC32 is selectively expressed in activated human regulatory T-cells (Treg), thus representing a bona fide Treg marker. GARP/LRRC32 binds LAP/latent TGF-beta [5].

Anatomical context of LRRC32

• The Garp gene is expressed in various areas in the mid-gestation developing embryo, including skin, lens fibre cells, nasal cavity, smooth and skeletal muscles, lung, and megakaryocytes of the fetal liver [4].
• GARP/LRRC32 is expressed not only on Treg cells, but also on platelets [6], the precursor of which interestingly also express FOXP3 [7], corroborating a close interelation between FOXP3 and GARP/LRRC32 in some cells [8]

Analytical, diagnostic and therapeutic context of LRRC32

• Sequence analysis has revealed that there are very few coding differences between different GARP genes [9].

References