TMEM144

Conceptual translation of Transmembrane Protein 144 mRNA transcript sequence with peptide sequence. DNA annotations mark an upstream in-frame stop codon, start codon, exon borders, stop codon, polyadenylation signals, and polyadenylation sites. Protein annotations mark the ten transmembrane domain regions, internal repeats, and the region of the protein excluded from the second isoform. Amino acids conserved in distant orthologs are bolded.

Transmembrane Protein 144 (TMEM144) is a protein in humans encoded by the TMEM144 gene.

Gene

Transmembrane Protein 144 is located on the plus strand of chromosome 4 (4q32.1), spanning a total of 40,857 base pairs. The TMEM144 gene transcribes a mRNA sequence 3,210 nucleotides in length and composed of 13 exons.

Protein

There exist two isoforms of human Transmembrane Protein 144. Isoform one consist of 345 amino acids with a total mass of 37.6 kDa. This isoform has a theoretical isoelectric point of 6.63. The second isoform is 169 amino acids long with a mass of 18.3 kDa.

Predicted tertiary structure of human transmembrane protein 144. Regions of dark blue are very high confidence, light blue regions are confident, yellow regions are low confidence, and orange regions are very low confidence.

Expression

TMEM144 is over-expressed in adult brain tissue with low regional specificity. TMEM144 appears enriched in oligodendrocytes and immune cells, such as dendritic cells and monocytes.

Cellular Localization

Precise cell localization has multiple predicted locations. Localization tools state TMEM144 is likely found in the plasma membrane, endoplasmic reticulum,Lysosome/Vacuole, or Golgi apparatus. However, an immunofluorescent staining of various human cell lines display localization to the mitochondria.

Post Translational Modifications

There exists five predicted post translational modifications for TMEM144, including four sites of phosphorylation and a sumoylation site.

Transmembrane Protein 144 schematic with transmembrane domains and predicted post translational modifications. P indicates predicted sites of phosphorylation. SUMO indicates a predicted sumoylation site.

Interacting Proteins

Several proteins have been observed to be physically associated with TMEM144, including Transmembrane Protein 237, Homocysteine-Responsive Endoplasmic Reticulum-Resident Ubiquitin-Like Domain Member 2 Protein, Translocase of Inner Mitochondrial Membrane Domain-Containing Protein 1, Free Fatty Acid Receptor 2, Aquaporin 6, Serine Rich Single-Pass Membrane Protein 1, and Adrenoceptor Beta 2.

Homology

Transmembrane Protein 144 arose approximately 694 million years ago in desert locust. It can be found in both vertebrates and invertebrates. It takes TMEM144 approximately 6.8 million years to make a 1% change to its amino acid sequence, indicating a moderately low rate of evolution.

Multiple sequence alignment of human Transmembrane Protein 144 with vertebrate orthologs. Some amino acids in the ortholog sequences were cut out at the N-terminus. Amino acids are highlighted by shared properties and structure. Consensus sequences denote highly conserved amino acids with a capital letter, moderately conserved amino acids with a lowercase letter, and low conservation with a dot. A plus or minus symbol in the consensus sequence indicates conserved basic (+) or acidic (-) properties. Transmembrane regions are boxed in orange and exon boundaries are marked in pink.

Multiple sequence alignment of human Transmembrane Protein 144 to invertebrate orthologs. Consensus sequences denote highly conserved amino acids with a capital letter, moderately conserved amino acids with a lowercase letter, and low conservation with a dot. A plus or minus symbol in the consensus sequence indicates conserved basic (+) or acidic (-) properties. Transmembrane regions are boxed in orange and exon boundaries are marked in pink.

Ortholog Table

Clinical Significance

Transmembrane Protein 144 is predicted to be a direct or indirect negative regulator of kisspeptin. High expression of TMEM144 is prognostically favorable for patient with endometrial cancer. Whereas in patients with pancreatic cancer, high expression of TMEM144 is associated with poor prognostic outcomes.