Major hyphal cell wall protein which plays a role of adhesin and is required for mating, normal hyphal development, cell-to-cell adhesive functions necessary for biofilm integrity, attachment to host, and virulence. Promotes interactions with host and bacterial molecules, thus leading to effective colonization within polymicrobial communities. Plays a crucial role in gastrointestinal colonization, in mucosal symptomatic and asymptomatic infections, in vaginitis, as well as in lethal oroesophageal candidiasis, caused by the combined action of fungal virulence factors and host inflammatory responses when protective immunity is absent. Hyphal surface. Localizes to the a/a Portion of the conjugation bridge during mating. Found in hyphal but not yeast forms. The promoter contains a 368 bp region, the HWP1 control region (HCR), which is target of transcription factors and is critical for activation under hypha-inducing conditions. Expression is positively regulated by BCR1, EFG1, FLO8, GPA2, GPR1, MSS11, RBF1, and RFG1; and negatively regulated by NRG1 and TUP1. Transcription is induced in an adhesion-dependent manner and in presence of human serum or hemoglobin. Expression is down-regulated by hypoxic conditions, allicine, ethylenediaminetetra-acetic acid (EDTA), farnesol, linalool, riccardin D, purpurin, filastatin, phorbasin H, Ocimum sanctum essential oil (OSEO), as well as many substances belonging to chemical classes such as methyl aryl-oxazoline carboxylates, dihydrobenzo-d-isoxazolones, and thiazolo-4,5-e-benzoisoxazoles. Moreover, the competitors Saccharomyces boulardii or Streptococcus mutans secrete respectively capric acid and trans-2-decenoic acid (SDSF) which also suppress HWP1 expression. The GPI-anchor is attached to the protein in the endoplasmic reticulum and serves to target the protein to the cell surface. There, the glucosamine-inositol phospholipid moiety is cleaved off and the GPI-modified mannoprotein is covalently attached via its lipidless GPI glycan remnant to the 1,6-beta-glucan of the outer cell wall layer. Serves as a substrate for mammalian transglutaminases which are necessary for cross-linking between HWP1 and host epithelial cells. Also predicted to be a substrate for cleavage by KEX2. N- and O-glycosylated. Reduces the overall mating frequency in both liquid and solid media. Impairs stable attachments to human buccal epithelial cells and reduces capacity to cause systemic candidiasis in mice. Produces a thin biofilm that lacks much of the hyphal mass found in the wild type cell. As a major cell surface protein expressed during infection, HWP1 detection can be used for diagnosis of invasive candidiasis. HWP1 epitopes can also be used to develop vaccines for protection against candidiasis. Belongs to the HWP1 family.