Transcriptional regulator involved in developmental processes. Functions in association with APBB1, SET and HDAC factors as a transcriptional repressor, that inhibits the expression of CASP4. TSHZ3-mediated transcription repression involves the recruitment of histone deacetylases HDAC1 and HDAC2. Associates with chromatin in a region surrounding the CASP4 transcriptional start site(s). Regulates the development of neurons involved in both respiratory rhythm and airflow control. Promotes maintenance of nucleus ambiguus (nA) motoneurons, which govern upper airway function, and establishes a respiratory rhythm generator (RRG) activity compatible with survival at birth. Involved in the differentiation of the proximal uretic smooth muscle cells during developmental processes. Involved in the up-regulation of myocardin, that directs the expression of smooth muscle cells in the proximal ureter. Involved in the modulation of glutamatergic synaptic transmission and long-term synaptic potentiation (PubMed:27668656). Interacts (via N-terminus) with HDAC1 and HDAC2; the interaction is direct. Found in a trimeric complex with APBB1 and HDAC1; the interaction between HDAC1 and APBB1 is mediated by TSHZ3 (By similarity). Interacts (via homeobox domain) with APBB1 (via PID domain 1). Colocalizes with APBB1 in the nucleus. Colocalizes with APBB1 in axonal growth cone (By similarity). Expressed in corticostriatal neurons. Expressed in branchio and viscero motoneurons at 10.5 dpc. Expressed in the nucleus ambiguus (nA) motoneurons at 15.5 dpc. Expressed in the brainstem respiratory rhythm generator (RRG), including two interacting neuronal networks constituting two oscillators: the pre-Boetzinger complex (preBoetC) at 15.5 dpc and the embryonic parafacial respiratory group (e-pF or pFRG) at 14.4 dpc, that contributes both to motor coordination of the respiratory apparatus and confers central chemosensitivity, as well as in cranial motoneurons targeting chest muscles that control the upper airway opening. Expressed in the developing urinary tract. Expressed in ureteric bud (UB) stalk at 11.5 dpc. Expressed in mesenchymal cells along and around the UB stalk, and absent from the UB epithelium and in scattered cells within the metanephric medullary stroma at 12.5 dpc. Expressed in mesenchymal cells in proximal ureters at 14 dpc, preceding the smooth muscle precursor cells differentiation and the expression of contractile proteins from 15 dpc. Expressed in mesenchymal cells of the ureter and renal pelvis, and in renal medullary stroma, in the mesenchymal cells adjacent to the epithelium and in the peripheral mesenchyme where smooth muscle (SM) starts to differentiate; the outer rim of nephrogenic mesenchyme was negative at 15.5. In the bladder, expressed in the submucosal loose connective tissue adjacent to the epithelium and in the detrusor SM layer at 18.5 dpc. Up-regulated by BMP4. Mice fail to breathe and die at birth. Display pronounced cell death of motoneurons in the nucleus ambiguus and induce strong alterations of rhythmogenesis in the embryonic parafacial respiratory group (e-pF or pFRG) oscillator and cranial motoneurons that control the upper airways. Mice also fail to form small smooth cells in the proximal ureter and urine flow is impaired because of functional obstruction caused by absent peristalsis in the proximal ureter that leads to hydronephrosis and hydroureter phenotypes. Belongs to the teashirt C2H2-type zinc-finger protein family. Life's first breath - Issue 122 of October 2010