9.B.112 The Stress-inducible Transmembrane Protein (TMPIT1) Family
A drought stress-inducible putative membrane protein was cloned from root tissue of wild emmer wheat. TMPIT1, the protein is a member of the widespread but uncharacterised TMPIT (transmembrane protein inducible by TNF-α) family. The TdicTMPIT1 gene is upregulated on drought stress in drought-tolerant wild emmer wheat, but not in a drought-sensitive accession or in cultivated durum wheat. The TdicTMPIT1 product is a membrane protein with four transmembrane helices.
Human Tmem120A and Tmem120B nuclear membrane proteins are found in fat cells, and both are induced during 3T3-L1 adipocyte differentiation. Knockdown of one or the other protein alters expression of several genes required for adipocyte differentiation. The double knockdown increased the strength of the effects, reducing, for example, Glut4 levels by 95% upon pharmacologically induced differentiation. The TMEM120A and B fat-specific nuclear envelope transmembrane proteins may play a contributory role in the tissue-specific pathologies (Batrakou et al. 2015).