In this Video the the components of JAK STAT Pathway have been discussed with detailed structure and functions.The JAK acronym comes form a protein named JANUS Kinase and STAT is acronym for Signal Transducer and Activator of Transcription.
Both JAK and STAT have different functions and different structures which have been comprehensively described in this lecture.
The JAK is the tyrosine kinase while STAT is the protein which gets activated by the JAK once it receives the cytokine signals from the extracellular region,

anus kinase (JAK) is a family of intracellular, nonreceptor tyrosine kinases that transduce cytokinemediated signals via the JAKSTAT pathway. They were initially named "just another kinase" 1 and 2 (since they were just two of a large number of discoveries in a PCRbased screen of kinases,[1]) but were ultimately published as "Janus kinase". The name is taken from the twofaced Roman god of beginnings and endings, Janus, because the JAKs possess two nearidentical phosphatetransferring domains. One domain exhibits the kinase activity, while the other negatively regulates the kinase activity of the first.

Members of the signal transducer and activator of transcription (STAT) protein family are intracellular transcription factors that mediate many aspects of cellular immunity, proliferation, apoptosis and differentiation. They are primarily activated by membrane receptorassociated Janus kinases (JAK). Dysregulation of this pathway is frequently observed in primary tumors and leads to increased angiogenesis, enhanced survival of tumors and immunosuppression. Gene knockout studies have provided evidence that STAT proteins are involved in the development and function of the immune system and play a role in maintaining immune tolerance and tumor surveillance.
All seven STAT proteins share a common structural motif consisting of an Nterminal domain followed by a coiledcoil, DNAbinding, linker, Src homology 2 (SH2), and a Cterminal transactivation domain. Much research has focused on elucidating the roles each of these domains play in regulating different STAT isoforms. Both the Nterminal and SH2 domains mediate homo or heterodimer formation, while the coiledcoil domain functions partially as a nuclear localization signal (NLS). Transcriptional activity and DNA association are determined by the transactivation and DNAbinding domains, respectively.